Malaysia's former attorney-general, who was suddenly removed from office last year, is reported to have put in place a plan to lay criminal charges of misappropriation against Prime Minister Najib Razak.
Abdul Gani Patail and the deputy prime minister of Malaysia - who would have replaced Mr Razak - were sacked before they could confront the Prime Minister, the ABC reported.
Mr Patail informed several senior officials on 23 July 2015 of his plan to confront Mr Razak at a cabinet meeting scheduled for 29 July.
Australian journalists who tried earlier this month to question Mr Razak about his personal finances were arrested and thrown out of the country.
There are four international investigations into the billions of dollars said to be missing from Malaysia's sovereign wealth fund, which has an advisory board chaired by the Prime Minister.
The office of Switzerland's attorney-general said its investigation had uncovered a "sum suspected to have been misappropriated [which] amounts to around $US4 billion [$NZ5.97b]".
"The criminal investigation conducted by the Office of the Attorney-General of Switzerland has revealed serious indications that funds have been misappropriated from Malaysian state companies," the office said.
"So far four cases involving allegations of criminal conduct and covering the period from 2009 to 2013 have come to light ... each involving a systematic course of action carried out by means of complex financial structures."
The controversy around Mr Razak emerged last year, when it was revealed that an unnamed donor from the Middle East had deposited more than $US680m into his account.
In January, Mohamed Apandi Ali, the new Malaysian attorney-general, said $US620m of this money was a "donation" from Saudi Arabia that was subsequently repaid, and that Mr Razak's account was closed.
He also shut down an investigation by Malaysia's anti-corruption agency into the affair.
Political observers and human rights groups have said Mr Razak's regime has resorted to a crackdown against anti-government voices.
Local newspapers and television stations rarely carry sceptical coverage of the government, while an Al Jazeera television reporter was deported from Malaysia last year.
Two weeks ago, a prominent and critical online news portal, Malaysian Insider, suddenly announced its closure.
"They've resorted to sheer intimidation and threats," said Clare Rewcastle-Brown, whose online Sarawak Report based out of London has led coverage of the corruption controversies surrounding Mr Razak.
"They're pulling charges out of the air to throw at people, and shoving people in jail."
In July last year, draft charges against Mr Razak were leaked to Ms Rewcastle-Brown which alleged he did "corruptly receive a bribe in the sum of RM27m", the equivalent of $NZ10m.
ABC programme Four Corners said it had independently corroborated the authenticity of this document.
The programme had also established that, in its final iteration, the charge adopted for action by the former attorney-general was changed to criminal misappropriation.
Mr Razak's office did not respond to questions from the ABC.