A man sustained serious injuries after he was beaten up by a group for insulting businessman Datuk Ong Teik Kwang who was shot dead, allegedly by his newly-hired bodyguard on Thursday.

In the 5pm incident the following day, the 47-year-old victim was assaulted at the Khoo Kongsi cemetery near the Thean Teik Highway in Air Itam here on Friday.

Penang CID chief SAC Zainol Samah said a police team went to the scene and rescued the man.

He said the man had sustained bruises, swelling and cuts in the region of the right eye, cheeks, nose, back and hands.

"The victim was taken to the Penang Hospital while the police have detained a man and are closing in on two others, all of whom were believed to be involved in the assault," he added in a statement here today.

He said investigations revealed the assault followed an "insulting" statement on the deceased, allegedly made by the victim on social media, which caused uneasiness among Ong's family members.

"We have also obtained a video recording showing the victim being beaten up by several men. The recording will be used as evidence in our investigations," said Zainol, who also rubbished claims the incident involved a fight between two rival secret society members.

On Thursday, Ong and two other men died while five other people were injured when they were shot by the bodyguard, believed to be mentally unstable, at the Tun Dr Lim Chong Eu Expressway at 7.15pm. -- BERNAMA