Former Malaysian leader Najib Razak insisted he was not the architect of the 1MDB scandal as took the stand to defend his conduct on Tuesday, as the first of several trials linked to the multi-billion-dollar fraud entered a crucial stage.

The 66-year-old's coalition was ousted at the polls last year after six decades in power, largely due to public anger over the scandal, and he has since been arrested and hit with dozens of charges linked to the looting of the investment vehicle.

What is the 1MDB scandal?

Huge sums were stolen from sovereign wealth fund 1Malaysia Development Berhad (1MDB), allegedly by Najib and his cronies, and spent on everything from high-end real estate to artwork.

The ex-prime minister went on trial in April over the controversy in a case centering on the transfer of 42 million ringgit (10.1 million U.S. dollars) from a former 1MDB unit into his bank accounts. He denies any wrongdoing.

The High Court ruled the trial should proceed on the strength of the prosecution case, with Najib's team now presenting his side of the story.

Defense proceedings began with the former leader giving testimony under oath. He will also face cross-examination from prosecutors and is expected to be on the witness stand for around four days.

Najib arrived at the court in a blue suit and held a brief Muslim prayer with supporters at the building's steps. "I am as prepared as I can be," he told AFP. 

He began his testimony reading from a 243-page statement, recalling his long career in politics and ministerial posts he held since 1978, including the post of finance minister.

Answering questions from his lawyer Muhammad Shafee Abdullah, Najib said he was not the architect of 1MDB, which was formed in 2009 after the government took over the Terengganu Investment Agency and renamed it.

What is Najib accused of?

Najib is facing four charges of corruption and three counts of money-laundering in the trial over former 1MDB subsidiary SRC International.

Prosecutors have argued that Najib wielded huge influence over the unit and knew that stolen money was being funneled from it into his accounts.

The former leader did not have to give testimony under oath, and could have opted instead to give a statement from the dock without being cross-examined, or to remain silent.

In an opening statement in court before Najib took the stand, Shafee said he will prove that Najib "did not misappropriate funds... either directly or indirectly" and "did not act dishonestly." 

The amount transferred to his account "was done without his knowledge or involvement" as the transactions "were being manipulated by third parties without his knowledge and approval," Shafee said. "Ultimately, we will pray for an order that (Najib) be acquitted and discharged of all seven charges."

Read more:

Malaysia targets US$5 bln in 1MDB-linked assets

Najib ordered to defend himself in 1MDB case

James Chin, a Malaysia expert from the University of Tasmania, said the decision to give testimony was a "risky strategy – it can go either way."

"He is a good performer, he is charming, but the judge may not buy it," he added. 

The case is one of several 1MDB-linked trials investigating Najib's conduct. The biggest opened in August, centering on allegations he illicitly obtained over 500 million U.S. dollars from the fund.

U.S. authorities, who are also investigating the fraud as money was allegedly laundered through the American financial system, believe 4.5 billion U.S. dollars was looted from the fund.

(With input from AFP)