KUALA LUMPUR, May 15 — Tun Dr Mahathir Mohamad told Prime Minister Datuk Seri Anwar Ibrahim again today to substantiate claims the former had enriched himself and his family while in power.

The former prime minister said Anwar has repeatedly failed to back up such claims when challenged to do so, but instead told Dr Mahathir to refute his allegations including by suing.

Dr Mahathir said his assets were known from previous declarations while in office, and that he was already suing Anwar for defamation over the claim.

"Therefore, I ask again, show proof that I had abused my power to enrich myself and family.

"If it is just talking on a stage without evidence, then anyone can do this. They are called ‘Mr Rhetoric’,” he said in a statement today.

On Saturday, Anwar accused Dr Mahathir yet again of siphoning billions for himself and his family while he was prime minister, this time adding that it was an open secret Dr Mahathir’s family owned "planes, ships, and firms worth billions of ringgit.”

On May 3, Dr Mahathir sued Anwar for defamation over allegations that the former and his family had earned billions of ringgit during Dr Mahathir’s first stint as the prime minister.