A digital artwork that splashed the names of jailed Hong Kong democracy protesters onto a massive billboard in the heart of the city has been taken down, the gallery behind the work confirmed on Thursday.

The move comes amid fears of political censorship and shrinking creative freedoms in the Chinese finance hub as Beijing cracks down on dissent following huge and often violent democracy protests in 2019.

"No Rioters", a video installation by American artist Patrick Amadon, was among a rotation of works shown on a massive 1,400-square-metre LED billboard on the side of a department store in the Causeway Bay shopping district.

The exhibit coincided with two large-scale art fairs in Hong Kong in what the government dubbed "Art Week", designed to attract overseas galleries and wealthy art buyers after years of pandemic curbs.

Francesca Boffetti of the Milan-based Art Innovation Gallery told AFP that Amadon's work had been taken down per the decision of the department store owners.

"We don't know if it was government intervention," she said on Thursday.

Earlier in the day, the artist wrote on Twitter that his work "was taken down today at the request of the government".

AFP has contacted Amadon, the Hong Kong government and SOGO Department Store for comment.

Amadon said on Twitter last week that he "managed to sneak pro-democracy protestors' names, ages, and purported crimes into the flashing text" of the video installation.

Wen Wei Po, a Beijing-backed newspaper in Hong Kong, on Wednesday said Amadon was expressing support for the protesters.

"According to a pro-Beijing outlet, I am 'pro-rioters'. This is correct," the artist wrote on Twitter shortly afterwards.

Names that flash across the screen in the 24-second video include activist Joshua Wong, legal scholar Benny Tai and other pro-democracy figures currently on trial for subversion under a Beijing-imposed national security law.

More than 10,000 people have been arrested in relation to the 2019 protests, with over 6,000 of them still waiting to see if they will face charges.

"No rioters, only tyranny" was a popular slogan used by Hong Kong protesters in 2019 to reject being labelled by authorities as "rioters".