The businessman father of a 15 year-old girl who fell 19 floors to her death says he is ‘distraught’ as he faces the prospect of losing a second daughter to social services while his wife remains in police custody. Nick Cousins, 57, was arrested over alleged 'ill treatment' of Blanca after it emerged police are investigating whether her birth, and that of her 14-year-old sister, were ever registered. It is also alleged that they did not attend school. She died in the early hours of Tuesday after falling from the family’s luxury apartment in Hong Kong. Mr Cousins was also questioned over claims that his Filipino partner, Grace Garcia Cousins, 53, had overstayed her visa by 20 years. Scroll down for video . Blanca Cousins, 15, who fell to her death from her family's flat in Hong Kong this week, told friends she went to an American school to explain why they never saw her in a uniform . A mother at the local pony club Blanca and her sister attended said that not even the sisters' closest friends knew they weren't going to school . He was released on bail yesterday pending police inquiries. Speaking for the first time, from the £7.5 million family home, he said: 'I am distraught. We all are. There is nothing else I can say.' Police yesterday applied for a 'care and protection order' for his second daughter but she has been returned home pending a second court hearing. Ms Cousins remained at a detention facility. Mr Cousins, originally from Thurrock, Essex, is managing director of the Hong Kong arm of international insurance broking firm Jardine Lloyd Thompson, and has worked for the firm in Asia for more than 20 years. It is understood that his partner moved to Hong Kong from the Philippines in the 1990s to work for Mr Cousins as a domestic helper before becoming his partner. It is unclear whether they had married, although she uses his surname. Their two children were both thought to have been born at a private hospital in Hong Kong. The couple were watching television in the family’s home, on the 19th floor of Hong Kong's most luxurious apartment buildings, when Blanca locked herself in a bathroom following a row at around 2am. She fell to her death from a window just before dawn. Paramedics declared her dead at the foot of the building in Repulse Bay Road. It is alleged British businessman Nick Cousins, 57, and Filipino Grace Garcia Cousins, 53, never registered the births of Blanca and her 14-year-old sister Carla . A police spokeswoman said a security guard found Blanca lying on the ground at the foot of the apartment . Police sources claimed while no suicide note had been found they were aware the girl had been 'unhappy' in recent weeks. Blanca – who was known as Blancs – was due to celebrate her 16th birthday in July. If their births were not registered, it means she would not have been able to attend school, travel abroad or receive medical treatment – unless paid for privately. School attendance is mandatory in Hong Kong, but a more relaxed approach is taken with expatriate residents and some 'home school' their children without official permission. She appeared to have enjoyed a relatively normal life, and seemed to have a wide circle of friends among the city’s well to do expatriate community. She was a member of the Hong Kong Pony Club and had recently attended Hong Kong Sevens rugby tournament, after her father secured a box there, and had invited friends to join her at the event. Today, the mother of a member of the Hong Kong Pony Club where the sisters attended regularly told MailOnline everyone at the club was shocked with the news. 'The two girls told us they went to an American school in Hong Kong and that was why they weren't wearing uniforms. They seem to have had it all planned,' the mother, who asked not to be named. 'Even one of the girls closest to Blanca did not know they weren't going to school. 'Blanca was a lovely girl and everyone is in absolute shock. We had no idea what was going on. At first we wondered if her death was down to cyber bullying, but when we found out the story we couldn't believe it at first. The girl's father has been named as Nick Cousins (pictured) the managing director of insurance broker Jardine Lloyd Thompson's Hong Kong office . 'I met the mother once at a pony camp but I never saw her again. Her dad was always here. He would pick the girls up after pony club and take them home. He was very kind and we thought they were a normal family with a dad that was involved with his children. 'Was it one lie that led to another lie? We simply don't know.' It is understood that she received private tuition with her younger sister. Yesterday, some of her friends paid tribute and expressed their shock at her death. Chiara Martin said on Twitter: ‘R.I.P Blanca Cousins You were a great friend and a sister to me’, posting a picture of Blanca nuzzled up to a pony. Charmaine Kima said: 'Such devastating news of Blanca and her family #RIPBlanca #staystrong.’ The 21-storey apartment block is one of the city's most prestigious addresses, with four-bedroom apartments selling for £7.5million each while they rent for £8,000 a month. Neighbours told the local Apple Daily newspaper that they would often see Blanca walking her dog ‘smiling’ or carrying books. They said her mother was ‘elegant’ and often accompanied her husband when he went out. They said she would talk to neighbours, but rarely spoke about their private life. Last night, police would not comment whether or not the girls were registered saying only that the matter was ‘under investigation’. Officers have applied for a ‘care and protection order’ for the youngest daughter. However the court is not due to rule on this until early May, and she has been returned to her family in the meantime. She is understood to be back at the family home with her father. Ms Cousins remained at a detention facility which houses illegal immigrants last night. A friend of the couple’s said yesterday: ‘The girls were/are adored by their parents, anyone knowing them knows this - but it’s a shock to even their close friends that they didn’t attend school, no-one knew this.’ This week, one expat who knows Mr Cousins described the family as 'down to earth and decent'. He added: 'He isn't a Hooray Henry at all, like so many of the expats in top jobs in Hong Kong. He's more of an Essex-boy type who worked his way up the corporate ladder and is just very bright and very good at what he does.' Tragedy: Blanca fell to her death in an apparent suicide early on Tuesday morning after locking herself in a bathroom of the apartment in Hong Kong's exclusive Repulse Bay Road (pictured) The 21-storey apartment is one of the wealthy city's most prestigious addresses with luxury four-bedroom apartments selling for prices in the region of £7.5million . A police source last night said: 'Initial investigations showed there were no suspicious circumstances and [Blanca] was suspected to have fallen from a height. 'We arrested a 53-year-old Filipino female for overstaying and a 58-year-old British male for aiding and abetting an overstayer. 'Both have also been arrested for suspected ill treatment of the girl. Our investigations indicate the girl was unhappy with her life.' Last night a spokesman for the Jardine Lloyd Thompson Group said: 'We can confirm that our colleague Nick Cousins, the managing director of our Hong Kong office, has suffered the loss of his eldest daughter in tragic circumstances. 'We are giving Nick our full support through this difficult time and he will be on compassionate leave until further notice. 'We are aware that the authorities are investigating a number of matters that have come to light in the wake of this tragic event. As these are private matters, it would not be appropriate for us to comment further. 'Our thoughts are with Nick and his family.' For confidential support call the Samaritans in the UK on 08457 90 90 90, visit a local Samaritans branch or click here for details.
Blanca Cousins fell to her death at exclusive address in Hong Kong .
Briton Nick Cousins, 57, and teen's Filipino mother, Grace, arrested .
Mr Cousins said he and his family are 'distraught' after their loss .
They may yet lose custody of their second child, Carla, aged 14 .
Blanca and her 14-year-old sister's births were allegedly not registered .
Teens didn't have passports and were educated at private tuition centre .
Police have said that Blanca may have been 'unhappy with her life'