HONG KONG (Reuters) - For anyone digging into Hong Kong s history, the official archives might not be the place to look. The office of the chief executive, Hong Kong s leader, failed to hand over any official records at all for eight of the 20 years since it came under Chinese rule in 1997, according to the government department that manages the archives. The Security Bureau only did it for 10. Researchers say the problem is that Hong Kong, under roughly 150 years of British colonial rule and the first 20 years of Chinese rule, has never had a law regulating how government records should be kept or destroyed. As a result, the document retention that researchers see as necessary for keeping a record of the past has been somewhat spotty within Hong Kong. Under British rule, the archiving of documents in Hong Kong was also lax. In 1994 and 1995, for example, the Government House gave nothing to the archives.  But thanks to a constant flow of correspondence between the colonial government and London, Britain would have stored a copy of most official records, according to researchers. After the handover of Hong Kong to China in 1997, that back-up mechanism disappeared, leading to concerns that fragments of Hong Kong s history might slip away for good.  Unlike Hong Kong, China has a set of archive laws, under which officials failing to file records can face administrative sanctions, or face charges if the case constitutes a crime.  But researchers say that for any Hong Kong-related documents kept by China, access would be difficult. Simon Chu, the former head of the Government Records Service who has been advocating for an archives law, said that prior to 1997 researchers could count on finding records in Britain, even if they were lost in Hong Kong.  After 1997, you don t have this kind of luxury,  he said.    Connie Lo, a documentary director digging into the 1967 Communist-led riots in Hong Kong, found almost nothing on the subject in the government archives. She was, however, able to find material in Britain s National Archives for her film  Vanished Archives,  which premiered in Hong Kong this year. Fears over record retention were highlighted last year when the government of former Chief Executive Leung Chun-ying said it had kept no records of informal meetings with local groups over a controversial land development project.  Hong Kong s current leader, Carrie Lam, has said she places  great importance  on the integrity of government records, and that she supports passing an archives law. She said she would pursue a law after receiving a report from the Law Reform Commission, which is studying the issue. The commission, however, has been considering the issue for four years and only expects to start consultations on the subject next year.  Activists like Chu are anxious that records of sensitive information, such as government decisions during the 2014 pro-democracy street protests could be destroyed with impunity.   I m very pessimistic about that,  Chu said. One former senior government official, speaking on condition of anonymity, also admitted to throwing out some documents in order to protect a former top official. He declined to say what the documents contained. But he suggested the practice might be widespread in the civil service.  For some of the most sensitive issues, there would not even be a record,  he said. The Government Records Service said it received 25 reports of unauthorized destruction of records in the past six years, and disciplinary actions were taken against four officers in four cases. 