The 78-year-old founder of the now-defunct Apple Daily newspaper was found guilty last month of collusion charges under a sweeping national security law, as well as one count of seditious publication.

Collusion offences "of a grave nature" will result in a prison term of between 10 years and life, while sedition comes with a maximum of two years.

Lai, a British citizen, has been behind bars since 2020, and multiple Western nations, including the United States and Britain, have called for his release.

The three-judge panel did not specify when they will sentence Lai and his eight co-defendants, which include six Apple Daily executives.

"There are a lot of legal issues... It's not an easy task," Judge Alex Lee said.

Defence lawyers conceded that the case -- which involved calls for foreign sanctions -- was likely of a "grave nature", meaning long jail terms.

All defendants except Lai pleaded guilty and some testified against him, which would entitle them to shorter sentences, the lawyers argued.

The court heard that associate publisher Chan Pui-man and her subordinate Lam Man-chung only played limited roles in the criminal conspiracy.

Chan, an award-winning journalist, sought a lenient sentence so she could take care of her elderly mother who suffers from dementia, her lawyer added.