Hong Kong's top court on Tuesday denied bail to Beijing critic Jimmy Lai — the most high-profile person charged under a new national security law.

The landmark case dramatically underlines changes the legislation has made to the common law traditions of semi-autonomous Hong Kong.

Lai has been in custody since December 3 last year, except for a period of about a week when he was granted bail. He was brought back into custody on December 31 after a hearing that followed an appeal from the Hong Kong government.

The return to custody was related to part of the security law stating that courts can only bail individuals if sure they will not "continue to commit acts endangering national security."

The Court of Final Appeal (CFA) judges on Tuesday said the lower court that bailed Lai had applied an "erroneous line of reasoning."

A small number of pro-China protesters outside the court shouted "Jail Jimmy Lai for life ... safeguard Hong Kong's peace" through a megaphone.

Inside the building, Lai's supporters chanted "Hang in there," and "Add oil," an encouragement that is used frequently in Hong Kong.

First legal test of new security law

Lai was initially arrested in August when some 200 police officers raided the newsroom of his Apple Daily tabloid newspaper.

Prosecutors accuse him of breaching the law over statements he made on July 30 and August 18. They allege that he requested foreign interference in Hong Kong's affairs.

Beijing imposed a sweeping national security law on the former British colony last June, following months of pro-democracy protests.

The legislation punishes anything that China considers subversion, secession, terrorism or collusion with foreign forces with a life prison sentence.

Legal analysts say the Tuesday's case serves as an indication of whether Hong Kong's judiciary could act as any kind of constitutional brake against Beijing's security law.

However, the judiciary can only interpret the territory's laws, which are usually passed by a semi-elected legislature.

rc/rs (AFP, Reuters, AP)