Hong Kong police on Thursday arrested a pro-democracy politician for allegedly inciting hatred against a police officer by exposing his identity online.

Democrat Cheng Lai-king, 60, chairwoman of the Central and Western District Council, is accused of "seditious intention" for having reposted on her Facebook account information of a police officer accused of injuring an Indonesian reporter during a protest last year.

"This is revenge taken by police," fellow Democrat lawmaker and councilor Ted Hui told reporters outside a police station while protesting Cheng's arrest. "Police use of the law which was targeting behavior against the British queen is unconstitutional."

The post in question, which has since been deleted, called for an "eye for an eye" and urged the police officer in question to "turn himself in," according to Radio Television Hong Kong.

Veby Mega Indah, associate editor of the Suara Hong Kong News, was left blind in one eye after being hit with a rubber bullet fired by police while covering an anti-government protest in September.

The police have declined to reveal the identity of the officer responsible for the shooting, citing a lack of evidence linking the shooting and the injury, despite Veby's requests.

Mohammed Swalikh, superintendent of the Hong Kong Police Forces' Cyber Security and Technology Crime Bureau, said inciting hatred and violence online is against the law and probably in breach of a court injunction order.

"If you look online, there are lots of words that are causing a lot of incitement...in the past eight, nine months," he told reporters. "That's why we have to take appropriate enforcement actions."

The colonial-era law under which Cheng has been accused defines seditious intention as attempting to "bring into hatred or contempt...against the person of Her Majesty" or the Hong Kong government or the administration of justice.

"The government of today decided that it would use these colonial laws to silence political discontent, clearly in political revenge for what the district councilors have been so bravely and courageously doing: their duty," Civic Party lawmaker Dennis Kwok said.