The director of a documentary about pro-democracy protests in Hong Kong defended his film on Friday as a truthful "historical" record after the citys police chief advised people not to watch it, citing what he described as possible legal risks. Fears of falling foul of a national security law imposed on the city by Beijing in 2020 have escalated, and some residents have said they have opted not to watch the film, "Revolution of our Times", in another sign of creeping self-censorship. "What kind of a world is it, if even watching a film at home is illegal?" Kiwi Chow told Reuters in an interview at his production house, stacked with DVDs of classic movies and film posters. "Its a basic freedom to watch a movie." Chows film, about Hong Kongs 2019 protests challenging what many city residents see as Chinas squeeze on the citys freedoms, was released internationally to critical acclaim at the Cannes Film Festival last July. It had not been available in Hong Kong, however, until June 1 when it was released on the video streaming site Vimeo. Under the security law, authorities outlawed the protest slogan "Revolution of our Times", which Chow made the films title, and authorities tightened censorship in October to "safeguard national security". Critics say the security legislation has eroded freedoms in the former British colony and led to scores of arrests, but authorities say it is needed to restore stability and safeguard its economy. Hong Kong police chief Raymond Siu told the South China Morning Post this week he would "advise" people not to watch or download the film if they werent sure about the legal risks. Police did not immediately respond to a request for comment. Too emotional The Vimeo website showed more than 81,000 views of the film as of Friday afternoon. Chow said he sold the films copyright to someone overseas. Some Hong Kong residents said the legal ambiguity had spooked them, with the possibility that online payments for the film could be traced. "I dont know if its illegal or not, or if authorities will find out," said Alan Yu, 40. One office worker who asked to be identified only by her surname, Ho, said her husband was worried after she bought the film online but had agreed to watch it. She said it stirred painful memories of a pro-democracy movement upon which many young people had pinned their hopes for the future. "I havent finished watching it. I watched the beginning and got too emotional and wanted to cry," she said. The fears stirred by the film in Hong Kong are a contrast with the reception it got in the democratic island of Taiwan, where it won a prestigious Golden Horse award and broke a box office record. Chow said he considers the two-and-a-half hour documentary his most important work after a two-year struggle to get it produced. "Films can record history, but they can also change history. I insisted on releasing it now to confront the current political environment. This is the power of film," said Chow. "My greatest hope is this film creates a dialogue with the viewers conscience," he said. He wants to continue directing in his hometown and has no plans to leave, as many people have done. Chow is aiming to lift spirits with his next film, a romantic comedy. "Perhaps sincerity and a sense of humor are needed in Hong Kong right now," he said. "At a time when so many lies are collectively told, we must be sincere and use humor to withstand this."