PUTRAJAYA • Tun Dr Mahathir Mohamad has been told to show proof to back up his claims against Prime Minister Najib Razak.

Datuk Seri S. Samy Vellu, who was a minister in Dr Mahathir's Cabinet, said yesterday that it was not fair for the former premier to hurl allegations without proof.

"Whatever Dr Mahathir wants to say, he has to provide evidence for it. If he wants to blame others, he must provide sufficient evidence, then we can see if it is right or not," he told reporters at the Prime Minister's Hari Raya open house yesterday, The Star reported.

Mr Samy Vellu led the Malaysian Indian Congress, a component party in the ruling Barisan Nasional, for some 30 years.

Dr Mahathir has attacked Datuk Seri Najib, particularly over debt- laden state investment agency 1Malaysia Development Bhd (1MDB).

There have also been calls for Mr Najib to go on leave temporarily to allow ongoing probes into the 1MDB issue to proceed smoothly.

"He does not need to be asked to go on leave. If every time something happens, and we ask the PM to take leave, the country will not survive," said Mr Samy Vellu, currently Malaysia's special envoy to India and South Asia on infrastructure.

His stout defence came after Dr Mahathir accused Mr Najib of being the "proxy" of Singapore and Malaysian businessman Low Teck Jho.

Dr Mahathir also said he did not ask Mr Najib to step down until the 1MDB scandal.

"Najib has his own advisers, including three Brits. He paid foreign consultants to advise him on government matters. He also asked Singapore whether he should build the bridge or the high-speed train. When Singapore said no, he shelved those projects. Jho Low is his friend and seems to have considerable hold on him," he wrote on his popular blog on Thursday.

"The fact is that he is their proxy, not mine. If he had behaved as my proxy there would have been no 1MDB etc," he added.