Digitally savvy Malaysian police have been taking to social media to issue warnings to critics of scandal-hit Prime Minister Najib Razak in an unusual online campaign that critics say is unlikely to work. Najib is facing the biggest political crisis in his seven-year premiership over a multi-billion dollar scandal at state fund 1Malaysia Development Berhad (1MDB) and over deposits of $681 million in his private bank account. Najib, chairman of the 1MDB advisory board, has denied any wrongdoing and says he did not take any money for personal gain. Attorney General Apandi Ali last week closed investigations of Najib and said the $681 million was a donation from a Saudi Arabian benefactor and most of it had been returned. That has not stopped Malaysians taking to social media to voice their exasperation. A caricature of Najib with a clown face and the words "in a country full of corruption, we are all seditious", was widely shared recently.

Human Right Watch said last month that Malaysia's human rights situation had deteriorated sharply in 2015, as the government stepped up a campaign of harassment and repression.

The government did not respond directly to that report but it denies violating rights.

Fahmi responded to his warning by reposting the clown and with a new sketch of the police with hashtag #BigBrotherIsWatchingYou.

No further action was taken against him while other artists expressed solidarity by sharing the clown sketch with the hashtag #KitaSemuaPenghasut, or "we are all seditious" in Malay.

Najib's Facebook page has over the months been flooded with criticism and calls on him to resign.

A former cabinet minister, Rafidah Aziz, said in a Facebook post on Monday that cracking down online would not work.

"It is so very naive to think that shutting down blogs and intervention in social media will actually stop people from talking," she said.

Salleh said the authorities took the law seriously.

"It is an offence ... to upload any comment, request, suggestion or other communication which is obscene, indecent, false, menacing or offensive in character with intent to annoy, abuse, threaten or harass another person," Salleh said.