On 29 July 2020, he became the first political figure to be arrested on suspicion of violating the newly imposed national security law[1] and has also been charged with money laundering and publishing seditious articles.

His first direct involvement in politics was in 2016 when he and some like-minded joined the campaign for localist camp candidate Edward Leung in the 2018 New Territories East by-election for the Legislative Council.

[3] Soon after the election in April 2016, Chung co-founded Studentlocalism with three other secondary school students which aimed to create a Hong Kong republic that would enjoy independent sovereignty.

The overseas branches announced that they would operate from abroad with divisions in Australia, Taiwan and the United States "until Hong Kong becomes an independent sovereign country.

It was speculated that the police arrested Chung for the social media content posted by the Initiative Independence Party who claimed to be founded by former Studentlocalism members who were based overseas.

The prosecutor read out the summary of facts for the charges, including social media posts dating back to 2016 which called for the public to join protests and push to "get rid of Chinese colonial rule," as well as the mission and manifesto of the Studentlocalism.

Names and amount of donations made to Chung's PayPal accounts with messages such as "keep it up" and "Hong Kong independence" were also read aloud at the court.

[10] On 24 November 2021, Hong Kong authorities jailed Tony Chung for three years and seven months after he had pleaded guilty to secession and one count of money laundering.