Najib said this in reference to a Wall Street Journal ( WSJ ) report earlier today alleging that US$700 million (RM2.6 billion) of 1MDB's fund was deposited into the prime minister's private accounts through proxies.
The prime minister shot down the allegation, stressing that he has never taken the government's money for personal gain.
"Let me be very clear: I have never taken funds for personal gain as alleged by my political opponents – whether from 1MDB, SRC International or other entities, as these companies have confirmed," he said.
Najib said the latest allegation is part of a series of "unsubstantiated and many simply outrageous" claims made against him and his family.
"These attacks began when I refused to implement Tun Mahathir’s personal demands.
"I refused, because I do not believe it is right for Malaysia to be ruled by proxy.
"Tun ( photo ) then created a crisis when he recklessly claimed that RM42 billion was missing from 1MDB, when in fact, these are audited debts backed by RM51 billion audited assets," said Najib.
He also cast doubt on the latest allegation, saying that an earlier claim of misappropriation against 1MDB based on leaked information from PetroSaudi International was allegedly tampered with.
"This says a lot about the reliability of the documents, and those who are using them to damage our government and our country," he said.
In recent months, various allegations – all unsubstantiated, and many simply outrageous – have been directed against me...
The leaked information included PetroSaudi's communications with 1MDB, which was used as evidence to allege that 1MDB's funds paid to PetroSaudi was later channeled to billionaire Jho Low, a close family friend of Najib's.
The information was published by whistleblower site Sarawak Report which has stood by its reports and challenged critics to sue the portal if they were untrue.
In the latest allegation published by WSJ , it alleged Najib received almost US$700 million of 1MDB's funds shortly before the 13th General Election.
"By far, the largest transactions were two deposits of $620 million and $61 million in March 2013, during a heated election campaign in Malaysia, the documents show.
"The cash came from a company registered in the British Virgin Islands via a Swiss bank owned by an Abu Dhabi state fund.
"Another set of transfers, totaling $11.1 million, originated within the Malaysian government, according to the investigation.
"Investigators believe the money came from an entity known as SRC International Sdn Bhd, an energy company that originally was controlled by 1MDB but was transferred to the Finance Ministry in 2012," WSJ reported.