The Communications and Multimedia Commission (MCMC) has temporarily blocked access to London-based whistleblower website Sarawak Report , following complaints by the public.
In a press release, MCMC said it had received complaints that the website had published information that has not been verified and are pending investigations.
"Access to this website is blocked temporarily, until the special task force completes its investigation," said the MCMC.
This is in reference to the joint agency investigations on 1MDB involving Bank Negara, the police, MACC and the attorney-general.
"In relations to this, the MCMC wishes to advise the public to be cautious when sharing information on social media, especially material which are not certain to be true.
"The contents could be fake. Such contents could cause affect the peace and cause national instability, disrupt public order and affect economic stability," said the MCMC.
Malaysian authorities have accused Sarawak Report of publishing "tampered" documents obtained from former PetroSaudi International Ltd (PSI) director Xavier Andre Justo.
Justo was nabbed in Thailand on June 22 and is being investigated by the Thai police for attempting to blackmail PSI with threats to release confidential company documents.
His arrest is of interest to Malaysia because PSI was involved in a failed joint-venture with 1MDB, a company wholly-owned by Putrajaya.
1MDB had invested US$1 billion into the JV vehicle, but US$700 were alleged diverted to another company. Two 1MDB directors had reportedly quit in protest as a result.
Quoting leaked PSI documents in March, Sarawak Report had claimed that the US$700 million went into the accounts of a company controlled by Jho Low, a known associate of Prime Minister Najib Abdul Razak.