The elder brother of businessman Wong Kwai-nam, who was jailed in 1996 for a hate mail campaign against officials including former chief secretary Anson Chan Fang On-sang, was ambushed by a gang outside his luxury apartment in Kowloon City yesterday. Wong Kwai-keung, 46, and his wife were driving home to One Beacon Hill at the time of the attack. His car was rammed from behind when it reached the entrance of the luxury housing estate just before 7am, according to police. 'Four to five men wearing surgical masks and carrying beef knives or water pipes jumped out from the car,' a police investigator said. 'As the victim and his wife would not come out, they smashed the windows, windscreens, doors and bumpers with weapons.' The assailants, thought to be aged between 20 and 40, fled in their car before police arrived. The couple were not hurt. Less than 10 minutes after police arrived, a car believed to have been used in the attack was found on fire under a footbridge in Chat On Estate, Shekkipmei. A police spokeswoman said the car had been reported stolen in Ho Man Tin on Monday night. Anti-triad officers from Kowloon City police station are investigating.