This comes after the Malaysian Commission of Multimedia and Communication (MCMC) blocks Sarawak Report and another foreign-based news website Asia Sentinel, which is critical of the Najib administration.

Communications and Multimedia Minister Salleh Said Keruak also said the government is looking to review the law so it can shut down websites which spread slander against national leaders.

"We suggest that, instead of these strong arm tactics against legitimate media coverage, Najib should move to restore his credibility by simply suing Sarawak Report in an independent court of law, in order that the evidence can be scrutinised and witnesses crossed examined.

"If Sarawak Report and other media are "lying", as is being suggested by Najib and his supports, then it would be the simplest thing for them to demonstrate that his reputation has been abused," Sarawak Report said in a statement today.

It added that failure to take legal action is tantamount to admission that the allegations the website raised are true.

"This is the time for him to resign," it said.

Sarawak Report has among others reported on allegations that funds flowed from 1MDB to the prime minister or companies controlled by his family friends.

Najib has denied any wrongdoing and has cooperated with the Malaysian Anti-Corruption Commission investigation into the RM2.6 billion found in his bank account and RM42 million said to be channeled to him from state-owned firm SRC International.

The Attorney-General's Chambers has returned the investigation papers for both cases for further clarification.

Sarawak Report cited sources as saying the MACC recommended no less than 37 charges against Najib, but the MACC has denied this