DIFFICULTIES may arise in the attempt to bring the prospective Official Secrets Act into line with the Basic Law, senior law lecturer at Hong Kong University Dr Nihal Jayawickrama said. He was speaking after the Secretary for Security, Alistair Asprey, revealed the Government's plan to move ahead with formulating a local version of the British law. Mr Asprey said: ''Local legislation to replace the UK Official Secrets Act has not been, and is not yet being, drafted. However, we have done some work on this subject, and I expect to put proposals to the Executive Council in the next few months.'' The draft amendment on the sensitive Crimes Ordinance, which includes the provisions on treason and offences against the government, will also be ready in about the same period. Dr Jayawickrama said it was necessary for the Government to introduce a local act on official secrets, but added that the timing might be difficult. Under the spirit of the Bill of Rights, the restrictions on access to government information should be kept as narrow as possible, he said. But Article 23 of the Basic Law stipulated that the future Special Administrative Region (SAR) Government should have its own legislation to ban the theft of state secrets. In view of the recent arrest in Beijing of a Hong Kong journalist for the publishing of articles on finance, Dr Jayawickrama said the Chinese definition of state secrets could be much wider than that adopted by other countries. ''If it is going to take into account the requirements of the Basic Law, I think it will be difficult,'' he said. Dr Jayawickrama called on the Government to work within the present legal framework by upholding the spirit of the Bill of Rights. The more wide-ranging restrictions, as stipulated in the Basic Law, should be introduced only after 1997. Responding to a question from United Democrat legislator James To Kun-sun, Mr Asprey said the matter would be discussed with China. United Democrats Lee Wing-tat questioned whether it would be an offence against the Crown to call for the downfall of the Queen or the Governor. Mr Asprey said he remembered no prosecution being made during the 1967 Hong Kong riots when such slogans were shouted.