Former Malaysian Prime Minister Najib Razak arrived at the anti-corruption agency's office Thursday for more questioning over a massive graft scandal at a state investment fund that he set up.

Najib, who was ousted in a shock defeat in May 9 national elections marked by public anger over the scandal, smiled and waved at reporters before entering the Malaysian Anti-Corruption Commission building.

He had been questioned there for more than four hours Tuesday, specifically over why 42 million ringgit ($10.6 million) was transferred into his bank account from SRC International, a former unit of the 1MDB fund, using multiple intermediary companies.

That transfer was in addition to some $700 million of 1MDB funds that U.S. investigators say landed in Najib's bank account. Najib set up 1MDB when he took office in 2009 but it accumulated billions in debts and is being investigated in several countries. The U.S. Justice Department say Najib's associates stole and laundered $4.5 billion from the fund.

Malaysia's new anti-graft chief has said Najib, who denies any wrongdoing, could face criminal charges "very soon."

Xavier Andre Justo, a whistleblower in the 1MDB case who met with new Prime Minister Mahathir Mohamad earlier this week, also turned up at the anti-graft agency Thursday just before Najib arrived. He didn't speak to reporters.

An anti-graft official, who declined to be named as the matter is sensitive, said Justo is assisting a taskforce investigating the 1MDB fiasco but couldn't give further details.

Najib Razak
Malaysia's former prime minister Najib Razak arrives to give a statement to the Malaysian Anti-Corruption Commission (MACC) in Putrajaya, Malaysia May 24, 2018. REUTERS/Lai Seng Sin

Najib and his wife were barred from leaving the country after the new government reopened an investigation into the scandal. Police have raided Najib's home and other properties linked to him, seizing hundreds of expensive designer handbags and luggage stuffed with cash, jewelry and other valuables.

New Finance Minister Lim Guan Eng said this week that Najib's government had conducted "an exercise of deception" over 1MDB and misrepresented the country's financial situation to parliament.

He said government debt had ballooned to more than 1 trillion ringgit ($251 billion) and that the finance ministry had bailed out 1MDB by paying nearly 7 billion ringgit ($1.76 billion) to service its debts since April 2017, contrary to 1MDB's claim that the money was from a rationalization exercise. 1MDB officials also told the ministry that the fund is insolvent and unable to repay millions more in debts due this year, Lim said.

In a statement on social media late Wednesday, Najib disputed the government debt figure and accused Lim of issuing "misleading statements."

"Saying that our debt is now 1 trillion ringgit without giving any details of what you mean will just unsettle the financial markets, alarm the credit rating agencies and investors' confidence in our institutions," Najib said.

"While you may want to slander and put all the blame on me to give a perception of a dire financial position to justify why you cannot deliver on your manifesto promises and to massively cut the civil service, you must remember that the country and our people comes first."

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