Former Malaysian Prime Minister Najib Razak has been questioned by anti-corruption authorities over a financial scandal after his shock election loss.

Najib was summoned to the Malaysian Anti-Corruption Commission (MACC) on Tuesday, specifically to answer questions about how $10.5m in government funds from the state-owned entity SRC International Bhd ended up in his private account.

"It's to provide statement, not to arrest him," MACC chief Mohd Shukri Abdull told reporters at a press conference.

"If we are satisfied with his answers, we can let him go. If we need further statements we will call him back again."

Dozens of journalists surrounded Najib as he arrived at the anti-corruption headquarters.

The questioning of Najib comes as Mohd Shukri revealed that witnesses have gone missing, and that he received death threats while pursuing the case implicating Najib in 2015.

"I was threatened to be fired, asked to retire early, take leave early, and be pulled into the training department," he said, referring to the SRC investigation.

SRC is a former subsidiary of the controversial state fund 1MDB, from which officials are alleged to have stolen more than $4.5bn.

In 2016, the US justice department filed a case seeking to seize more than $1bn in assets in the US linked to the 1MDB fund.

US investigators have also alleged that $700 million from the 1MDB fund ended in Najib's bank account.

Najib, who is banned from leaving the country, has denied allegations of wrongdoing.

'No deal with Najib'

An attorney general appointed by Najib in 2016 had cleared him of wrongdoing, saying a particular transfer of $681m was a political donation from the Saudi royal family and that most of it was returned.

On Wednesday and Thursday, Malaysian police seized bags of cash, jewellery and hundreds of luxury handbags during a series of raids at several properties of Najib as part of the government investigation.

New Prime Minister Mahathir Mohamad, however, said investigations showed the wrongdoing at 1MDB were more serious than expected.

Mahathir said former attorney-general Abdul Gani Patail had told him he was preparing to press charges against Najib when he was abruptly fired in 2015.

Mahathir, who was prime minister for 22 years until 2003 and was spurred out of retirement by the 1MDB scandal, has vowed there will be "no deal" for Najib, and he will face the consequences if found guilty of wrongdoing.

The current attorney general has been put on leave, and Abdul Gani was appointed as a member of a new task force investigating the state fund.

The US justice department said in a statement that it looks forward to working with Malaysian law enforcement in investigating the 1MDB case.

A March 2018 investigation by The Wall Street Journal had revealed that top Republican fundraiser close to US President Donald Trump, Elliott Broidy and his wife, Robin Rosenzweig, had sought $75m in payments from a Malaysian financier Jho Low, for the US justice department to drop the case into 1MDB.

A new investigative report published by Associated Press news agency says Broidy was part of campaign led by Saudi Arabia and United Arab Emirates to undermine Qatar. He was one of President Donald Trump's top fundraisers.

Broidy's lawyer has responded saying the AP report is based on "fabricated documents".

PHOTO CAPTION

Former Malaysian Prime Minister Najib Razak

Al-Jazeera