Masked attackers hurled petrol bombs at the home and media HQ of Next Media founder Jimmy Lai Chee-ying in coordinated attacks in the early hours of Monday morning.
In the first attack at 1.45am, two men pulled up outside Lai's home on Kadoorie Avenue before one, wearing a surgical mask and a hood to hide his features, set fire to something sticking out of a bottle before throwing it at the gates.
The contents of the bottle exploded in flames which were quickly extinguished by security guards.
Five minutes later a similar firebomb was thrown at the gates of Next Media in Chun Ying Street on the Tseung Kwan O industrial estate.
The attackers then drove to another entrance and threw another firebomb.
Two cars suspected to have been used in the attacks were later found torched on Chak On Road in Shek Kip Mei, and Sham Mong Road in Cheung Sha Wan.
Firefighters were called to tackle the blazing vehicles and investigators discovered the licence plates had been removed.
Police said the motive for the attacks was still under investigation. No arrests have been made.
Lai stepped down as chief executive officer and chairman of the board of Next Media following his participation in the pro-democracy Occupy protests last year.
A statement released on December 14 said Lai "has decided to step down from his executive positions of the group so as to spend more time with his family and further pursue his personal interests".
The previous day Lai had been arrested - along with other leading supporters of the Occupy civil disobedience campaign - when police cleared a protest camp in Admiralty.
The company's flagship titles Apple Daily and Next Magazine had supported the pro-democracy movement.