Hong Kong's Apple Daily newspaper said Jimmy Lai, the founder of Next Media, was picked up from his home by officers at around 7 am and taken to a police station in the Kowloon neighbourhood.
Hong Kong's Apple Daily newspaper says the outspoken head of its publishing group, Jimmy Lai, has been held by police on Friday over his participation in a protest march in August that was part of a months-long pro-democracy movement.
The paper said Lai, the founder of Next Media, was picked up from his home by officers at around 7 am and taken to a police station in the Kowloon neighbourhood.
It also said the vice-chairman of the opposition Labor Party, Lee Cheuk-yan, and others were also detained at the same time in connection with the August 31 march, called to mark the fifth anniversary of a decision by China against fully democratic elections in Hong Kong.
Organisers called off the action after the police banned it, but hundreds of thousands of people defied the order and filled the streets in several areas of the Asian financial hub. Protesters threw gasoline bombs at government headquarters and set fires in the streets, while police stormed a subway car and hit passengers with batons and pepper spray in some of the most violent scenes up to that point in the protest movement.
Hong Kong broadcaster TVB showed police on the platform of Prince Edward subway station swinging batons at passengers who backed into one end of a train car behind umbrellas.
The video also shows pepper spray being shot through an open door at a group seated on the floor while one man holds up his hands.
Police arrested thousands during the protest movement that began in June but fizzled out toward the end of the year amid harsher tactics by authorities. Still prison sentences have been against many on charges including rioting and possessing offensive weapons.
The demonstrations began to oppose proposed legislation which would have allowed Hong Kong residents to be sent to mainland China to stand trial, but later included demands for democratic elections and an investigation into police use of force.
Lai is a serial entrepreneur and longtime activist who sold his clothing chain under political pressure and has since focused on media in Hong Kong and Taiwan.
There was no immediate comment from Hong Kong police.