Hong Kong tycoons among five charged with corruption July 13, 2012 -- Updated 0801 GMT (1601 HKT) Raymond Kwok (left) and Thomas Kwok rank as the 27th richest people in the world, according to Forbes. Thomas and Raymond Kwok among five people charged with a total of eight offenses The billionaire brothers own Sun Hung Kai Properties, Asia's biggest property developer The investigation in Hong Kong focused on land purchases in the city Hong Kong (CNN) -- Two billionaire brothers who control Asia's biggest property development company have been charged with corruption, anti-bribery officials in Hong Kong said Friday. Sun Hung Kai Properties (SHKP) co-chairmen Thomas and Raymond Kwok were among five people charged with a total of eight offenses, including conspiracy to offer advantages to a public servant and misconduct in public office, the Independent Commission Against Corruption (ICAC) said in a statement. Hong Kong's former chief secretary Rafael Hui, banker Francis Kwan and Thomas Chan -- responsible for land acquisitions for SHKP -- were the other men charged after one of the biggest anti-graft probes in the banking hub's history. Tycoon arrests rock Hong Kong Hui, the city's former No.2, faces charges related to misconduct in public office, including the acceptance of rent-free apartments and unsecured loans. All five men were granted bail after a hearing on Friday afternoon, with the court case adjourned until October 12. Hui and Kwan were instructed to surrender their passports. The ICAC revealed the offenses took place between 2000 and 2009 as investigators probed land sales overseen by Hui involving SHKP. The case has caused a media frenzy in the city, where real estate is a local obsession. Sun Hung Kai, which helped to build some of the tallest buildings in the city's celebrated skyline, contributed to the Kwok brothers' estimated $18.3 billion fortune. The brothers, who were arrested in March, have protested their innocence. I can say that personally I have done nothing wrong. And I can vouch for Mr. Thomas Kwok that he has done nothing wrong either," Raymond Kwok said at a news conference on April 3, referring to his brother. "I hope this investigation will clear my name," he said. Hong Kong, a special administrative region of China, is considered to be one of the world's least corrupt territories. According to Transparency International's 2011 Corruptions Perceptions Index, Hong Kong is the 12th least corrupt territory in the world -- with the United States, by comparison, ranked 24th. CNN's Andrew Henstock and Tim Schwarz contributed to this report.