Ma Chun-man was sentenced to five years in prison for “inciting secession” under a Beijing-decreed national security law introduced in 2020.

Ma would normally have been eligible for a one-third reduction in his sentence for good behaviour but a second national security law passed by Hong Kong’s legislature earlier this year raised the bar for remission in national security cases.

The new law stipulates that people found guilty of national security crimes should not be granted remission unless the commissioner of correctional services is confident that doing so would not endanger national security.

Ma sought a judicial review of correctional authorities’ denial of his request for early release, arguing he was not properly informed about the decision.

In a decision on Friday, high court judge Alex Lee dismissed Ma’s challenge, finding that the new rules for remission were “sufficiently precise and certain” and that the decision-making process was “not procedurally unfair”.

“There is no question of Mr Ma being subject to any additional or heavier penalty by operation,” Lee, one of a number of judges hand-picked by the city’s leader to hear national security cases, said in his decision.

As of June, 300 people had been arrested for security-related offences since the introduction of the national security laws, with more than half of them charged, according to police statistics.

Western governments and human rights groups have criticised the laws for curtailing rights and freedoms that were supposed to be guaranteed as part of the terms of the former British colony’s return to Chinese rule.

Beijing and Hong Kong officials have defended the laws as necessary to restore stability to the city after antigovernment protests that often turned violent.

Justin Sun outbid six others to claim Maurizio Cattelan’s infamous 2019 work Comedian – a banana duct-taped to a wall – at Sotheby’s auction house in New York.

He ate the fruit during a news conference in Hong Kong where he used the moment to draw parallels between the artwork and cryptocurrency.

The banana is regularly replaced before exhibitions, with Mr Sun buying the right to display the installation along with a guide on how to replace the fruit.

It has been eaten twice before – first by a performance artist in 2019 and again by a South Korean student in 2023 – but neither paid any money to do so, let alone $6.2m.

“Eating it at a press conference can also become a part of the artwork’s history,” Mr Sun said.

“It’s much better than other bananas,” he added.The 34-year-old said he was intrigued by the work, admitting he had “dumb questions” about whether the banana rotted.

The New York Times reported a fresh banana was bought for 35 cents on the day of last week’s auction, before becoming possibly one of the most expensive fruits in the world.

Each attendee at the event on Friday was given a banana and a roll of duct tape as a souvenir.

“Everyone has a banana to eat,” Mr Sun said.

Mr Sun runs the Tron blockchain network – a service where users can trade in cryptocurrency.

Cryptocurrencies are digital currencies that operate independent of banks, offering the potential of very secure decentralised transactions.

Mr Sun compared the artwork, and other abstract pieces like it, to NFTs.These “non-fungible tokens” are pieces of digital artwork that have no intrinsic value, other than that prescribed by people.

NFTs can be traded on platforms like Mr Sun’s.Last year, he was charged by the US Securities and Exchange Commission for offering and selling unregistered security tokens. Mr Sun denies the charges and the case is ongoing.

This week, Mr Sun disclosed he made a $30m investment in a crypto project backed by US President-elect Donald Trump.