Australian Prime Minister Malcolm Turnbull should avoid meeting Prime Minister Najib Abdul Razak at the Asean-Australia Special Summit in Sydney this weekend, Pakatan Harapan chairperson Dr Mahathir Mohamad said.

In an interview with Australia’s ABC News, Mahathir said Najib often took the opportunity to be photographed with global leaders and advised Turnbull against helping to boost his counterpart’s image.

“He’s been trying to do that all the time. Having photo opportunities and all that.

“Because he wants to show Malaysians that he is well accepted,” said Mahathir when asked whether he had concerns that Najib’s meeting with Turnbull would enhance his credentials on the world stage.

“But if you know a man is a thief, he (Turnbull) should stay away from him (Najib),” said Mahathir, who insisted that Najib must be removed as prime minister over his alleged involvement in the 1MDB scandal.

In contrast, Mahathir reportedly told The Australian last week that Turnbull should "definitely" raise the 1MDB scandal with Najib at the summit.

Najib has denied any wrongdoing linked to 1MDB and attorney-general Mohamed Apandi Ali had also cleared him of all related offences.

Turnbull’s son, Alex Turnbull, had previously claimed that he was a victim of the 1MDB scandal, after being allegedly sidelined when he blew the whistle on purported misconduct within Goldman Sachs in Singapore over its dealings with 1MDB.

However, Goldman Sachs denied Alex’s claims and said that he was never involved in any 1MDB-related transactions.

In the interview, Mahathir was also asked whether he had changed his previous “dismissive” stance towards Australia’s attempts to join Asean.

In response, Mahathir said the focus should instead be on Asean's relationship with Australia.

According to Wisma Putra, Najib is scheduled to undertake a working visit to Sydney this weekend, accompanied by his wife Rosmah Mansor, Foreign Affairs Minister Anifah Aman, as well as various other government officers.