The asset freeze, announced on Friday, includes all shares in his company, Next Digital - the first time a listed firm has been target by national security laws in the financial hub.

Shortly before the announcement, the Taiwan arm of Lai's popular Apple Daily said it would stop publishing its print version, blaming declining advertising revenue and more difficult business conditions in Hong Kong linked to politics.

In a statement sent to Reuters, Taiwan's Mainland Affairs Council said the asset seizure highlighted the threat Hong Kong's national security law posed to the property of the city's people.

"It is equivalent to announcing to the international community that Hong Kong's business risks are increasing," the council added.

"We also once again call on relevant parties to stop suppressing Hong Kong democrats, otherwise they will drift away from popular sentiment."

Hong Kong has been rocked by anti-government protests in recent years and last year China imposed a tough new national security law on the city.

China denies it is aimed at taking away people's freedoms and is needed to return law and order to Hong Kong.

Lai was earlier sentenced to 14 months in prison for taking part in unauthorized assemblies during pro-democracy protests in 2019.