Security Secretary Chris Tang on Wednesday said he doesn't think it's correct to say that the arrest of another former Apple Daily editor will spread "white terror" in the media industry, as a journalists' group called for an end to such action.

The Hong Kong Journalists Association (HKJA) said it was shocked to hear that a former executive of the defunct newspaper had been detained by national security police, weeks after several others were arrested and two charged with "conspiring to collude with foreign forces".

Sources identified the latest man held as Lam Man-chung, a former executive chief editor of Apple Daily, which closed down last month.

The association said in a statement that it was baffled by the move, and it called on the authorities to "stop spreading white terror" in the media.

The HKJA said freedoms of the press and to publish are important cornerstones of a successful metropolis like Hong Kong and the authorities should explain how legal and constitutionally protected journalistic work is able to threaten national security.

But asked about the "white terror" claim, Tang said he did not think this was correct.

"Everyone, disregarding his profession, as long as he's committing an offence, we have the obligation to arrest them and prosecute them if there's evidence," he said.