After nearly a decade of troubles surrounding 1MDB, caretaker prime minister Najib Abdul Razak has said that in hindsight, he would have made some changes to the company.

"I would have probably not had that kind of business model, probably I would make sure (that there is) tighter supervision," he told US-based media outlet Bloomberg in an interview.

"But we all learn from our mistakes."

Indeed, 1MDB has been an expensive mistake for Malaysia. Conceived in 2009 soon after Najib came to power, the company quickly racked up RM42 billion in loans.

By 2015, the company was struggling to pay back its creditors and many of its assets had to be hastily sold off as part of what Putrajaya termed a "rationalisation exercise".

However, the main grouse with 1MDB was allegations that its funds were subject to gross abuse, in particular allegations documented by the US Department of Justice.

Among others, the DOJ accused an unnamed top-ranking official, simply identified as 'Malaysian Official 1', of receiving US$731 million in funds allegedly misappropriated from 1MDB. 

The exchange between Bloomberg and Najib on this follows:

Bloomberg: What do you say to those who claim that you have acted dishonestly about the funds. You have been called all sorts of things, including a thief.

Najib: There is no evidence of that. You cannot just accuse somebody of being a thief unless there is evidence. Again, if I can quote Tan Seng Giaw, he said we have to act on evidence and they could not find any evidence of wrongdoing.

Bloomberg: You have admitted that the funds did end up in your accounts even though it was a donation from the Saudi government.

Najib: It has been cleared. There was no wrongdoing. I stand by it. The Saudi government has come up with a statement admitting that it is an official donation. So, the fact speaks for themselves. But it has become a political issue.

Although the DOJ has been seizing 1MDB-linked assets across the world, and punitive action taken against banks or bankers linked to 1MDB funds in Singapore and Switzerland, no one has been charged with any offences in Malaysia.

In mid-2015, Najib sacked attorney-general Abdul Gani Patail, who was part of a widely published special task force investigating 1MDB.

Gani's replacement, Mohamed Apandi Ali, cleared Najib of any wrongdoing involving 1MDB, and police investigations into 1MDB have come to nought.

Najib said that 1MDB's problems should not distract attention away from the "huge number" of successes that his administration had achieved in other areas. 

On the DOJ investigations, Najib said: "We are willing to cooperate with them. our opponents influenced them in many ways.

"As long as investigations is done fairly and according to international protocols, we are willing to cooperate."