A 76-year-old Malaysian man has been arrested by the police in Kampung Tunku, Petaling Jaya for sharing a crude photo insulting Prime Minister Najib Razak in a WhatsApp group.

Johor police chief Commissioner Wan Ahmad Najmuddin Mohd said the suspect, who has been identified as Pa Ya, shared the photo in a WhatsApp group titled, "Bicara Politik Melayu" (Malay political discussion).

"The photo has insulted and hurt the feelings of Malaysians," he told AFP on Sunday. He added that the suspect's mobile phone was seized.

The suspect was remanded at the Johor Baru court on Sunday for investigations under Section 233 of the Communications and Multimedia Act 1998. If convicted, he might have to pay a maximum fine of RM 50,000 (S$16,900) or up to a year's jail, or both.

Commissioner Wan Ahmad also said they have formed a task force to closely monitor, identify and take action against those who misuse social media.

"I advise the public against misusing social media applications without thinking about the consequences. We will not hesitate to take action and eventually charge those who do," he added.