HONG KONG--Hong Kong police briefly arrested a 60-year-old pro-democracy district councilor on suspicion of “seditious intention,” the first person ever cited under the city’s colonial-era law, drawing widespread criticism from activists.

Police confirmed the arrest of Cheng Lai-king, chairwoman of the Central and Western District Council, under the offense. They declined to provide further details, saying an investigation was under way.

Cheng, who has not been formally charged, was freed on Thursday after more than 10 hours in custody and declined comment.

Separately, police confirmed on social media that the Secretary for Justice filed a lawsuit against an unnamed woman for contempt of court against “doxxing” of police.

Doxxing refers to publicly releasing private or identifying information about an individual or organization.

Local media reports said Cheng shared a Facebook post recently that contained details of a police officer who was accused by some people on social media of firing a projectile that hit Indonesian journalist Veby Mega Indah during anti-government protests in September last year.

No such post was visible on Cheng’s Facebook page on Thursday.

Veby is blind in one eye as a result of the incident.

Pro-Beijing lawmaker Elizabeth Quat said on her Facebook page she had filed a complaint against Cheng, accusing her of violating an injunction order of the Office of the Privacy Commissioner for Personal Data.

The injunction was imposed last year to prevent people from sharing the personal details of police officers and their families after some came under attack when their identities and contact details were exposed by protesters.

The offense of seditious intention, which carries a fine of HK$5,000 ($645 or 70,887 yen) and a jail term of up to two years, was outdated and unconstitutional, Democratic Party lawmaker Ted Hui said.

The law refers, among other things, to anyone who excites disaffection against “the person of His Majesty, or His Heirs or Successors, or against the government of this colony.”

Hui condemned the arrest as an abuse of police power and lacking any legal basis.

Hong Kong, a former British colony, was returned to Chinese rule in 1997 under a “one country, two systems” principle, with the guarantee of a high degree of autonomy and freedoms not enjoyed elsewhere in China.

Protesters in the global financial center are angry at what they see as increased meddling in the city’s affairs by Beijing, which it denies.

Protests over a now-scrapped extradition bill escalated in June last year but have evolved into calls for greater democracy. The outbreak of the coronavirus epidemic has largely stalled demonstrations so far this year.