Photo 
 
 SEOUL, South Korea — Did a fight over a puppy lead to the vote to impeach South Korea’s leader? A whistle-blower whose account has riveted South Koreans says it did. 
 
 The corruption scandal that engulfed the president, Park Geun-hye, was rooted in her friendship with Choi Soon-sil, her secretive adviser and friend for 40 years. Ms. Choi has been indicted on charges of extorting tens of millions of dollars from big businesses, and prosecutors have identified Ms. Park as a criminal accomplice, a first for a South Korean president. 
 
 Ko Young-tae, the whistle-blower, said at a parliamentary hearing this week that he got into an argument with Ms. Choi over walking her daughter’s puppy one day in 2014. He said Ms. Choi became upset when she found the dog alone at his home. 
 
 “I didn’t get her call because I was out golfing,” he said. “She was angry that I left the dog alone, and we had a fight.” 
 
 Mr. Ko, 40, a former Asian Games gold medal fencer, said afterward he decided to expose Ms. Choi’s ties with Ms. Park to local news media. 
 
 Advertisement Continue reading the main story 
 
 Mr. Ko had apparently videotaped Ms. Choi in 2014 giving orders to two presidential aides as though they were servants. In one scene that went viral, one of the aides wiped his smartphone on his shirt before handing it reverentially to Ms. Choi. The footage, aired in October on TV Chosun, left little doubt about Ms. Choi’s influence over Ms. Park. 
 
 Mr. Ko also was said to have an advance copy of Ms. Park’s itinerary for an overseas trip that Ms. Choi had received; it showed that the president had worn certain colors on certain days based on Ms. Choi’s recommendations. 
 
 Mr. Ko has become a hero to many in South Korea. “You opened Pandora’s box,” Sohn Hye-won, an opposition lawmaker, said during the hearing. 
 
 Photo 
 
 Even before he gave his account, Mr. Ko had emerged as an intriguing figure in Ms. Park’s corruption scandal, which has involved as many plot twists as the best of Korean soap operas. Local media said he was a former employee at a Seoul “host bar,” where male prostitutes cater to female clients, before he befriended Ms. Choi, 60. 
 
 In his testimony, Mr. Ko denied that he and Ms. Choi had been a couple. 
 
 He said a friend introduced him to Ms. Choi in 2012, when he was running a handbag and clothing company called Villomillo. Ms. Choi ordered 100 pieces of clothes and 40 handbags made of ostrich skin and crocodile leather. The items were delivered to Ms. Park, who was later seen toting Villomillo handbags. 
 
 (Ms. Park’s office said she paid for the items, denying opposition lawmakers’ allegations that they were bribes from Ms. Choi.) 
 
 Mr. Ko said he handed over his video footage to TV Chosun last year, but it was not broadcast until Oct. 25. 
 
 A day earlier, on Oct. 24, the rival cable channel JTBC broadcast what was considered the biggest media scoop connected to the scandal. One of its reporters obtained a discarded tablet computer that it said had belonged to Ms. Choi. 
 
 Advertisement Continue reading the main story 
 
 Files discovered there included drafts of 44 speeches and statements that Ms. Park had given between 2012 and 2014, as a candidate and later as president. Many passages were marked in red. 
 
 “The only thing Ms. Choi did well was to edit President Park’s speeches,” Mr. Ko told JTBC in October. (Ms. Park has since acknowledged that she asked for Ms. Choi’s feedback on her speech drafts.) 
 
 South Koreans were outraged that Ms. Park let Ms. Choi, who had no experience in government, edit some of her most important speeches. The allegation was particularly damning because Ms. Park was known for shunning one-on-one meetings with her own official aides. 
 
 Mr. Ko said Ms. Choi’s behavior made him believe she was the most powerful person in Ms. Park’s government. 
 
 “She insulted me and acted as if her underlings were subhuman,” Mr. Ko said. ||||| Image copyright Getty Images Image caption Mr Ko has denied he had an affair with presidential confidante Choi Soon-sil 
 
 The political scandal engulfing South Korea has culminated in Park Geun-hye's impeachment but according to one account, it all started with an argument over a puppy. The BBC's Tessa Wong unravels an outlandish series of events. 
 
 With his good looks and athletic build worthy of any South Korean pop star, Ko Young-tae has been the object of public fascination for months. 
 
 The former national fencer is closely linked to Choi Soon-sil, 60, the presidential confidante who now faces corruption charges. 
 
 Rumours about Mr Ko, 40, have saturated local media, which even labelled him Ms Choi's "toy boy". 
 
 But this week in front of a parliamentary committee he denied they were a couple. 
 
 Then, he proceeded to tell the extraordinary tale of how an argument prompted him to go to the press with revelations that would ultimately lead to the president's impeachment. 
 
 Read more: What is South Korea's presidential scandal? 
 
 Read more: The friendship behind the presidential crisis 
 
 Dressing the president 
 
 According to Mr Ko it all began in 2012, shortly after Ms Park was elected president. 
 
 Mr Ko, an Asian Games gold medallist, had long retired from fencing. His day job at that time was running a handbag and clothing company called Villomillo. 
 
 One day a friend asked him to show some of Villomillo's latest products to a mysterious buyer. 
 
 Image copyright Getty Images Image caption Mr Ko has been the object of public fascination since the scandal blew up 
 
 "My friend asked me to bring some new items (to a designated place), so I did. That's when I saw Choi for the first time," Mr Ko recounted at a public hearing this week. 
 
 Ms Choi liked what she saw, and he began supplying her with items which would end up in Ms Park's wardrobe. 
 
 He gave around 40 luxury handbags made of ostrich skin and crocodile leather, and 100 bespoke pieces of clothing to the president. 
 
 They cost tens of thousands of dollars, and Ms Choi paid for all of them out of her own pocket, according to Mr Ko. 
 
 Image copyright AFP/Getty Images Image caption Ms Choi is accused of influence-peddling 
 
 He strongly denied that he and Ms Choi became a couple - they were just friends, he said. 
 
 But he did not deny that she trusted him enough to give him appointments in two Germany-based companies which she owned. 
 
 As Ms Park's unofficial clothier Mr Ko also began to enjoy fame and success, especially after Ms Park was spotted toting a Villomillo bag in 2013, according to local media reports. 
 
 The brand drew celebrity customers and Mr Ko became a member of the local entertainment scene, even joining a celebrity baseball team called Play Boys. 
 
 'Puppygate' 
 
 In perhaps some of the most extraordinary testimony heard in South Korea's parliamentary chamber, Mr Ko described how trouble was brewing between him and Ms Choi. 
 
 In 2014, the businesswoman asked him to take care of her daughter's puppy. Mr Ko brought the dog to his house, then left it there as he went out to play a round of golf. 
 
 When he returned, he found Ms Choi in his home, furious with him for abandoning the puppy. The two had a "huge fight", he said. 
 
 From then on their relationship went downhill. "She treated me like a slave, swearing at me many times," he said in his candid account. 
 
 Angry and hurt, Mr Ko decided to exact revenge by going to the press about Ms Choi and Ms Park's relationship. 
 
 Image copyright AP Image caption The scandal is centred on the close relationship between Ms Park and Ms Choi 
 
 Over the months he collected evidence of Ms Choi's power over Ms Park's administration, including CCTV footage of Ms Choi treating presidential aides as her personal servants. He eventually turned them over to a local broadcaster. 
 
 Then, in October, he did a TV interview where he alleged Ms Choi's "favourite thing" was to edit Ms Park's presidential speeches. 
 
 Reporters went digging for evidence to back it up, and obtained a tablet containing selfies of Ms Choi and files of presidential speeches. 
 
 The discovery, along with other revelations of Ms Choi's allegedly suspicious business dealings, sparked public outrage and launched a wide-reaching corruption inquiry that has ensnared even corporate bigwigs and celebrities. 
 
 Ms Park later admitted she gave Ms Choi inappropriate government access - including to her speeches - and apologised. But she has denied the allegations of corruption that prosecutors have laid down. 
 
 Image copyright Getty Images Image caption Parliamentarians have voted to impeach Ms Park 
 
 The president has now been impeached, while in another twist Mr Ko is seen as a public hero, hailed by netizens for his "whistleblowing". 
 
 One lawmaker during the public hearing even praised him for "opening Pandora's box". 
 
 Asked in parliament if he feared opposing Ms Choi, the woman who had the president's ear, Mr Ko said "No". 
 
 "I was hot-tempered and never thought about that part," he declared. "I have no regrets." ||||| The ouster of South Korean President Park Geun-hye by the country's Constitutional Court on Friday ends a power struggle that consumed the nation for months. 
 
 Her removal from office over a corruption scandal has the potential to reshape a country whose politics have long been marred by fraud and ideological bickering. 
 
 The changes may begin with a presidential by-election expected in early May. 
 
 It is a stunning downfall for Park, a conservative who convincingly beat her liberal opponent in 2012. 
 
 READ MORE: Park Geun-hye - I have never conspired with anyone 
 
 No longer immune from prosecution, she may soon find herself in a criminal court defending charges that she colluded with a confidante to extort money and favors from companies and allowed the friend to secretly manipulate state affairs. 
 
 Here's a look at key developments in a memorable, tumultuous stretch in South Korean politics: 
 
 July 27, 2016: A TV news channel reports on suspicions that one of Park's former senior secretaries pressured large companies into donating to K-Sports, a nonprofit organisation aimed at internationally promoting South Korean sports. 
 
 September 20: A newspaper reports that Choi (pronounced Chwey) Soon-sil, Park's longtime friend, was involved in establishing and running K-Sports. 
 
 October 24: Another TV station, citing files found from a tablet computer, reports that Choi, who has no official government role, received classified government information such as advance drafts of presidential speeches. 
 
 October 25: Park publicly acknowledges her close ties with Choi, and says Choi helped her on speeches and public relations issues during her 2012 presidential campaign and after her 2013 inauguration. 
 
 October 27: State prosecutors launch a special investigation team to look into the scandal. 
 
 October 29: First of what becomes a series of large anti-Park rallies is held in Seoul. 
 
 READ MORE: Rival protests in Seoul over Park Geun-hye impeachment 
 
 October 30: Choi returns to South Korea from Germany. Two days later, while being rushed into a Seoul prosecutors' office, she tells reporters she "committed a sin that deserves death". 
 
 November 4: Park in her second apology over the scandal expresses remorse, but denies that she was involved in any legal wrongdoing. 
 
 November 20: In indicting two former Park aides and Choi, state prosecutors say they believe the president was "collusively involved" in criminal activities by the suspects, who allegedly bullied companies into giving tens of millions of dollars to foundations and businesses Choi controlled, and enabled Choi to interfere with state affairs. Park's lawyer calls the accusations groundless. 
 
 December 3: Opposition lawmakers formally launch an attempt to impeach Park, setting up a floor vote. Massive crowds said to be more than 2 million demonstrate across the nation calling for Park's ouster. 
 
 December 9: Lawmakers pass the impeachment bill on Park by a vote of 234 for and 56 opposed. The Constitutional Court begins preparations for Park's impeachment trial. 
 
 January 1, 2017: In a surprise New Year's meeting with reporters, Park accuses her opponents of framing her. 
 
 January 5: The Constitutional Court begins hearing arguments in Park's trial. One of Park's lawyers compares her impeachment to the "unjust" deaths of Jesus Christ and ancient Greek thinker Socrates. 
 
 READ MORE: What's next for South Korea? 
 
 January 16: Choi, Park's jailed friend, appears in the impeachment trial and denies accusations related to her. 
 
 January 25: A former culture minister tells court Park's office blacklisted thousands of artists deemed as unfriendly to her government with an intention to deny them state support. 
 
 February 17: Lee Jae-yong, the billionaire scion of Samsung, South Korea's largest business group, is arrested over suspicions that he bribed Park and Choi in exchange for business favours. 
 
 February 22: One of Park's lawyers tells court there will be a "rebellion and blood will drench the asphalt" if the court unseats Park and she is later acquitted of her charges through a criminal proceeding. Court closes arguments five days later. 
 
 March 10: The eight-member Constitutional Court votes unanimously to remove Park from office.
– The impeachment of South Korean President Park Geun-hye, and the scandal surrounding it, all comes down to a canine. Park's downfall started over ties with Choi Soon-sil, a close friend for decades embroiled in criminal controversies and secretly advising Park—and who got into an argument with the eventual whistleblower over her daughter's pup, the New York Times reports. Ko Young-tae relayed his story at a parliamentary hearing last week, noting he and Choi got into a tiff after she discovered the dog, which he'd been asked to walk, alone in his apartment while he was out golfing. He says that after they exchanged words, he decided to come forward with what he knew about Choi and Park. Ko, 40, an ex-member of the nation's fencing team and called Choi's "boy toy," had worked at a Seoul "host bar," where male workers entertain female customers with conversation and sexual services. The Korea Times says he reportedly met Choi at one of those bars in 2006, though he testified last week he'd been introduced to her by a pal in 2012 (and he denied at last week's hearing they were ever a couple, per the BBC). Regardless of how they met or their official status, their relationship allowed him to reportedly get his hands on Park's clothing choices for a trip overseas, as well as videotape of Choi ordering two presidential aides around; he turned that footage over to a Korean cable network, which aired it in October. "She insulted me and acted as if her underlings were subhuman," he said in his testimony, adding that after the dog fight, she "treated me like a slave, swearing at me many times," per the BBC. Some of his compatriots say Ko is a national hero for his revelations. "You opened Pandora's box," one lawmaker said during the hearing.