Lawyer Mohd Haniff Khatri Abdulla has demanded an apology from attorney-general Mohamed Apandi Ali and issued a challenge to Apandi to re-open the case on Prime Minister Najib Abdul Razak.

This follows the Singapore Court's reported conviction of Swiss banker Jens Fred Sturzenegger in a 1MDB related probe.

In a statement, Haniff claimed that facts of the Singapore case had contradicted Apandi's decision last year to clear Najib of allegations surrounding the RM2.6 billion that was deposited into the prime minister's personal bank accounts.

"Apandi's statement on Jan 26, 2016, whereby the attorney-general had decided to not take any action against Najib over the RM2.6 billion in his personal accounts, on grounds that it was a 'donation (from) an Arab' is now proven false by the conviction in Singapore's court," Haniff said.

He claimed that facts of the case, which allegedly implicated Najib,were in contrast with Apandi's claim, which has yet to be proven in any court of law.

Last Wednesday, Sturzeneggar pleaded guilty to concealing these facts, as well as to five other charges, and was slapped with a 28-week jail sentence and a S$128,000 fine.