Hong Kong national security police on Wednesday arrested a former editor at the now-defunct Apple Daily pro-democracy newspaper, weeks after the paper was forced to close after authorities froze its assets.

Lam Man-chung, who was the executive editor-in-chief of Apple Daily, was arrested on suspicion of conspiring to collude with foreign forces to endanger national security, according to the South China Morning Post newspaper, which cited an unnamed source. He was the eighth person from the newspaper to be arrested in recent weeks.

Two other former Apple Daily journalists - deputy chief editor Chan Pui-man and chief editorial writer Fung Wai-kong - were also detained on Wednesday after their bail was revoked, according to local media reports.

Ms Chan was among the five Apple Daily executives and editors arrested on June 17, and Mr Fung was first arrested at the airport late last month while allegedly attempting to leave on a flight to the UK.

Police said that a 51-year-old former editor was arrested on Wednesday in relation to a similar case in June, but did not identify the person arrested.

In June, police raided the newspaper's offices, taking away hard drives and laptops as evidence.

The arrests of top executives, editors and journalists at the paper, as well as the freezing of 2.3 million dollars (£1.69 million) worth of assets, led Apply Daily to cease its operations last month. It sold a million copies of its final edition.

Following months of anti-government protests in 2019, Beijing last year imposed a sweeping national security law in Hong Kong which critics say restricts the freedoms promised to the former British colony that are not found on mainland China.

More than 100 pro-democracy supporters have been arrested, and many others fled abroad.