Hong Kong¡¯s top court overturned the convictions of three former members of a pro-democracy group, marking a rare victory in challenging the enforcement of the national security law imposed by Beijing.

The Court of Final Appeal on Thursday unanimously quashed the convictions of three defendants, including barrister Chow Hang Tung, who were sentenced to four-and-a-half months in prison for failing to assist with a national security probe.

The case centered on the government¡¯s demand in 2021 for funding and meeting records of the Hong Kong Alliance, a now-disbanded group that organized annual vigils commemorating Beijing¡¯s 1989 Tiananmen Square crackdown. Police claimed the group was a ¡°foreign agent¡± under the implementation rules of the security law, an allegation denied by the defendants.

A panel of five judges found that prosecutors must prove the organization is actually a foreign agent ¡ª not merely believed to be one by police ¡ª for the charges to stand.

The court also ruled that redactions of key facts by government lawyers, including the identities of overseas groups allegedly linked to the Alliance, were ¡°self-defeating¡± and made a fair trial impossible.

Chow, who has already served the sentence along with Tsui Hon-kwong and Tang Ngok-kwan, represented herself at the appeal. The former head of the Hong Kong Alliance remains behind bars pending a subversion case against the group and faces life imprisonment.

The Beijing-drafted national security law authorized the local government to make implementation rules, which also empower police to search places for evidence, freeze assets and remove messages online.

More than 100 people have been charged under the law since it entered effect in 2020, and only two people have been acquitted so far.

The Court of Final Appeal separately upheld a conviction of former activist Tam Tai-chi under a colonial-era sedition law, which has since been repealed when the city passed the Safeguarding National Security Ordinance last year.