Legal scholar and Chinese People's Political Consultative Conference (CPPCC) member Albert Chen on Friday said the National Security Law can be amended, and that won't have retroactive effect.

His comments came a day after the SAR's top court overturned the convictions of three former members of Hong Kong Alliance in Support of Patriotic Democratic Movements in China for refusing to hand information to the police in a national security investigation.

In response, the Hong Kong government said it will study the ruling, review how it enforces national security laws, and look for ways to improve them.

Speaking to RTHK in Beijing, Chen said the Court of Final Appeal's ruling is reasonable and aligns with common law principles.

Asked whether changes are needed, he said Hong Kong's Committee for Safeguarding National Security is in charge of making rules for the National Security Law.

"Laws can be amended at any time. Of course, these amendments won't have retrospective effect. But after the amendment, the court will need to make rulings based on the newly amended laws," the University of Hong Kong professor said.

This committee can decide to change the rules on its own without seeking approval from the National People's Congress, Chen added.