The Hong Kong Court of Final Appeal denied pro-democracy publisher Jimmy Lai’s request for bail on Tuesday.

Lai was arrested in August under the controversial National Security Law (NSL) and charged with fraud and “collusion with a foreign country or with external elements to endanger national security.” The court granted and subsequently revoked Lai’s bail between December and January. Lai returned to custody in January to await his February 1 hearing.

On Tuesday, the court ruled that Judge Alex Lee, who originally granted Lai’s bail, “misconstrued” Article 42 of the NSL as equal to the less stringent standard set out in the Criminal Procedure Ordinance (CPO). The court explained that the CPO rule “embodies the presumption in favour of bail” while Article 42 of the NSL presumes that “no bail shall be granted to a criminal suspect or defendant unless the judge has sufficient grounds for believing that the criminal suspect or defendant will not continue to commit acts endangering national security.”

Lee’s ruling wrongly interpreted Article 42 “into a positive requirement that the court has to be satisfied that there do exist grounds to believe that the accused will continue to commit acts endangering national security as a basis for refusing bail.” Due to the misreading of the NSL, the court ruled that Lee never made a proper judgment on Lai’s bail request.

Under the ruling, Lai will remain in custody but may continue to seek bail.