KUALA LUMPUR • Malaysian Prime Minister Najib Razak has launched a scathing attack on Tun Dr Mahathir Mohamad, accusing the former premier of backing jailed leader Anwar Ibrahim because of fears Anwar could testify against him in an inquiry about foreign exchange losses.

"Dr Mahathir knows that the RCI (Royal Commission of Inquiry) findings could lead to criminal prosecution, so he cannot afford to have individuals highly relevant to the case, such as Anwar, testifying against him," Datuk Seri Najib said in a statement issued on Friday.

Last month, the Prime Minister's office said that an RCI would be convened to look into the billions of ringgit in foreign exchange losses incurred by the central bank in the 1980s and 1990s when Dr Mahathir was prime minister.

"It is ironic that Mahathir now needs Anwar, the man he sacked and jailed," Mr Najib said. "Just as he now needs Lim Kit Siang, another man he jailed, because in reality, Kit Siang controls the opposition as DAP (Democratic Action Party) has the vast majority of parliamentary seats - whereas Mahathir's party has just one," he said.

Dr Mahathir founded Parti Pribumi Bersatu Malaysia last year, which is part of the opposition coalition Pakatan Harapan, together with the DAP, Anwar's Parti Keadilan Rakyat and Parti Amanah Negara.

In an interview with British daily The Guardian published on Thursday, Dr Mahathir said Anwar should be released from jail, and allowed to contest elections as he was a victim of a political vendetta.

Anwar is seen as the greatest threat to Mr Najib and his coalition, after leading an opposition alliance to stunning electoral gains in 2013. Anwar was once a protege of Dr Mahathir, but they fell out in the late 1990s. He was then jailed for the first time on charges of sodomy and graft, after being sacked as the deputy prime minister. He denied the charges, dismissing them as politically motivated.

He was jailed in 2013, when Mr Najib was Prime Minister, after another sodomy conviction, also seen as a politically motivated move .

Opposition to Mr Najib however, has drawn Anwar and Dr Mahathir together.

Mr Najib said Dr Mahathir has "no principles" and "is obsessed with... making his son Mukhriz Mahathir prime minister". He also said that Dr Mahathir "will do anything, including allying with those he jailed, calling for foreign intervention in our sovereign democratic nation, sabotaging our economy and making 100 U-turns if so required to manipulate people's minds - just as a means to achieve his desired ends".

Dr Mahathir has been trenchant critic of the Prime Minister, frequently levelling allegations of financial mismanagement and graft at the government because of the scandal involving state fund 1Malaysia Development Berhad.

Mr Najib has denied any wrongdoing in connection with the 1MDB affair.

THE STAR/ASIA NEWS NETWORK, REUTERS