Following a massive protest movement in 2019, Hong Kong authorities launched a crackdown on dissent and have taken nearly 3,000 people to court over the span of five years.

More than 800 have been charged with rioting, a crime broadly interpreted by local courts to cover many of those present at scenes of violence.

Jackie Chen, 48, was part of a small group of social workers who appeared on Hong Kong's tense street standoffs in 2019 carrying loudhailers, urging police to stay calm and to allow time for protesters to leave.

After being arrested in August 2019, she pleaded not guilty and argued that she was trying to de-escalate clashes and did not intend to participate in riots.

She was acquitted in 2020 but her case was sent to a retrial after prosecutors won on appeal.

Deputy district judge May Chung ruled Tuesday that Chen had shouted "provocative" words that wrongly implied police had used excessive force.

"Through her words and acts, (Chen) expressed her support of the protesters... which bolstered their determination and confidence to resist the police," the judge wrote.

The judge said Chen brought a gas mask and wore a t-shirt that read "We are social workers defending justice", which showed she had prepared for the protests.

Circumstantial evidence led to the overriding conclusion that Chen intended to take part in the riot, the judge wrote.

Those found guilty of rioting in the district court face a maximum prison term of seven years.

After the verdict, Chen told supporters in the public gallery to "take care".

"Just because (the government) disagrees with us, that doesn't mean we did anything wrong," she told AFP before the hearing, adding that she would face the outcome with equanimity.

Chen was remanded in custody for sentencing on April 9.

She previously criticised the government's decision to push for a retrial, saying that younger co-defendants were kept from moving on with their lives.