HANOI (Reuters) - Vietnam began the trial on Monday of 22 executives charged over losses totaling hundreds of millions of dollars at the state oil firm, PetroVietnam, with the most serious offences potentially carrying the death penalty.

A policeman directs traffic in front of a court in Hanoi, Vietnam January 8, 2018. REUTERS/Kham

The defendants included the communist state’s first politburo member to face trial in decades and a businessman who Germany says was kidnapped by Vietnamese agents from a Berlin park.

The trial is part of a widespread crackdown on fraud and mismanagement in the energy and banking sectors that intensified after the security establishment gained greater influence in the ruling party last year.

The PetroVietnam trial in Hanoi was taking place simultaneously with a separate trial in the commercial capital Ho Chi Minh City, where a fraud case involving Vietnam’s Construction Bank was being heard.

The 46 defendants include the bank’s ex-chairman Pham Cong Danh, who is accused of causing losses of 6.1 trillion dong ($268.62 million), according to the government’s news website.

Total losses caused by fraud at the bank amounted to 15.5 trillion Vietnam dong ($682.55 million), a previous report said.

The PetroVietnam case at the Hanoi People’s Court was not open to the public and security was tight.

Photographs released by the Vietnam News Agency, the official state news provider, showed defendants handcuffed as they were led to the courtroom.

Of the 22 executives on trial, 12 are accused of “violation of state regulations on economic management causing serious consequences”. Eight are accused of embezzlement, according to the government’s official news website. Two are accused of both.

The most senior former executive on trial is Dinh La Thang, who was arrested last month. He is a former politburo member who was dismissed from his post over the losses at PetroVietnam and then stripped of his role as party head of Ho Chi Minh City.

Also on trial is Trinh Xuan Thanh, who Germany says was kidnapped last year and taken home against his will to face accusations over losses of more than $150 million at a subsidiary of PetroVietnam.

Thanh is accused of both corruption and breaking state rules on economic management. A Reuters reporter saw the bespectacled Thanh arrive under police escort at the court on Monday.

Thanh appeared on state television in August and said he had decided to return home to turn himself in.

Neither Thang nor Thanh made any comment at the court and Reuters was unable to contact the lawyers representing them.

The maximum jail term for deliberate violation of state regulations is 20 years in prison, state television VTV1 reported in a news bulletin on Monday.

Government critics have voiced suspicions that the corruption crackdown is politically motivated, at least in part, and aimed against those close to former prime minister Nguyen Tan Dung, who lost out in an internal power struggle in 2016.

The trial is due to last until Jan. 21.

In a separate case linked to the corruption crackdown, a fugitive Vietnamese tycoon was arrested in Hanoi on Thursday after being sent home from Singapore, where he was accused of immigration offences.

Phan Van Anh Vu, 42, told his lawyers he was also a senior officer in Vietnam’s secret police and was trying to get to Germany and could have details of the operation in which Thanh was spirited home from Berlin last year.

($1 = 22,709 dong)