HANOI (Reuters) - A former Vietnamese politburo member on trial over the loss of hundreds of millions of dollars at state oil firm PetroVietnam has testified that a key decision was taken by the previous prime minister, according to video published on local media.

Vietnamese policemen stand guard outside the court in Hanoi, Vietnam January 9, 2018. Picture taken January 9, 2018. REUTERS/Kham

Dinh La Thang is the most senior politician to face trial in decades, having been caught in a widening crackdown on corruption that intensified last year after Communist Party General Secretary Nguyen Phu Trong emerged as the winner in a power struggle with former prime minister Nguyen Tan Dung.

Thang is accused of deliberate mismanagement alongside 21 others who face the same charge, charges of embezzlement or both, in what is the most important trial of a widening crackdown on corruption.

He was asked by the court on Tuesday about the decision to assign the PetroVietnam Construction (PVC) subsidiary to the contract for the Thai Binh 2 thermal power plant project when it did not have the capacity to carry out the project.

“Assigning PVC was the right policy, with the decision of the Prime Minister of the government,” according to video published by local media. Thang also described it as “the policy of the politburo” - of which he was not a member at the time.

Thang told the court that his impatience had led to the violation of regulations. Only state-backed media are allowed into the court hearings, but other Vietnamese media are allowed to watch a video feed in an adjacent room.

Reuters was unable to contact former prime minister Dung for comment.

Scores of people have been arrested in the anti-graft campaign as the security establishment gained influence after Trong defeated Dung in a power struggle for the Communist Party’s top position in 2016.

Government critics have noted that many of those detained had prospered under Dung’s administration.

Among the other officials on trial is Trinh Xuan Thanh, the former chairman of PetroVietnam Corruption, whose case grabbed world headlines last year when Germany accused Vietnam of kidnapping him from a Berlin park.

Thanh denied accusations made by witnesses in the court on Tuesday that he had handled bags of money sent as bribes to officials, the local VNexpress website reported. Thanh is accused over losses of more than $150 million.

A document reviewed by Reuters last year showed that Thanh had been cleared of wrongdoing by the previous government.