Next Digital, the parent company of Hong Kong’s popular pro-democracy tabloid Apple Daily, saw its shares rocket on Monday in an apparent show of support by investors after a raid on its offices by Hong Kong police and the arrest of its founder, media tycoon Jimmy Lai.

The group’s shares, which are traded on the Hong Kong Stock Exchange, closed up 183% at HK$0.26 at the end of the trading session in Asia after news broke that Lai had been arrested under a controversial new national security law on suspicion of “colluding with foreign forces”, which carries the potential sentence of life in prison.

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Lai has been a prominent and outspoken advocate for democracy in the city, frequently appearing at and supporting demonstrations while also criticising the Chinese Communist Party and the Hong Kong government.

Meanwhile, hundreds of police officers descended on the Apple Daily offices in a mass raid, sparking fears that the new law is serving to undermine press freedom in the city, despite prior claims that the media would not be targeted.

In a statement, Next Digital accused the police of “breaching press freedom through intimidation and creating an atmosphere of white terror”, adding that the authorities had “blatantly bypassed the law and abused their power, despite claims about acting according to the rules”.

“Beijing’s national security law for Hong Kong claims to guarantee residents’ freedom of speech, of the press and of publication, but the authorities’ actions have proved otherwise. Raiding a news institution is a severe attack on press freedom and should not be tolerated in a civilized society. The regime believes that we will be silenced by intimidation and harassment, and that they can take an international city down the path of autocracy. Hong Kong’s press freedom is now hanging by a thread, but our staff will remain fully committed to our duty to defend the freedom of the press”, the company added.

Meanwhile, London listed firms that have previously backed Beijing’s imposition to enact the national security law, which has resulted in multiple arrests in Hong Kong, were faring less well, with shares in HSBC Holdings PLC (LON:HSBA) up just 0.3% at 326p in mid-afternoon trading while fellow bank Standard Chartered PLC (LON:STAN) was up 1% at 404.7p.