KUALA LUMPUR • Malaysia's former prime minister Mahathir Mohamad and his wife have returned two awards they received from the Selangor palace, an aide to the politician said yesterday, in an escalating tiff between the senior politician and the ruler.

Selangor's Sultan Sharafuddin Idris Shah has been unhappy with remarks made by Tun Dr Mahathir, labelling the Bugis people as "pirates", when he was attacking Prime Minister Najib Razak.

This is because the Selangor ruler's family also has Bugis roots.

Dr Mahathir made the remarks in October, when he was attacking Datuk Seri Najib over the alleged theft of public money from state fund 1Malaysia Development Berhad.

The former premier, in one of his regular attacks against Mr Najib, had reportedly said: "Maybe he (Mr Najib) can trace his ancestry to Bugis pirates. Somehow, he lost his way and came to Malaysia. Go home to Bugis."

The Bugis people originated from what is today Indonesia's South Sulawesi province.

Sultan Sharafuddin said in a statement last month issued by his royal council that Dr Mahathir had "clearly insulted and bracketed the Bugis as a people who originated from pirates, robbers and criminals".

It added: "This allegation indirectly insulted the ancestral roots of the Selangor sultanate which was founded by the Bugis."