Secretary for Justice Paul Lam on Saturday insisted Hong Kong's legal system is "very liberal" as foreign lawyers are still allowed to take part in national security cases.

The country's top legislature passed an interpretation of the national security law last year, saying courts need approval from the Chief Executive to allow foreign lawyers without the full qualifications for pracitising in Hong Kong to take part in such cases.

Speaking on an RTHK radio programme, Lam said the SAR should strike a balance between safeguarding national security and leveraging the advantages of its common law system.

He said letting overseas lawyers take part in security cases helps Hong Kong to maintain its international status.

"We have a system which is not shared by most other law jurisdictions. In principle, we still retain the system to allow overseas lawyers to come to Hong Kong," he said.

"We introduced the system under which the circumstances of each case will be assessed individually, so there is still a real chance for overseas lawyers to come to Hong Kong, even if to allow him to come to Hong Kong to appear in that particular case may involve national security. So our system, even under our amendment, is very, very liberal."

Lam said other regions and countries have even stricter regulations on foreign lawyers, and cited Singapore as an example, saying the city-state bans overseas lawyers from taking part in all criminal and family cases.