The latest sentence will be part of his total 30-year imprisonment. Thang had previously received three jail terms for different violations. The Hanoi People's Court said in a ruling that his jail time would begin on December 8, 2017, the date of his arrest.

Former chairman of Petrovietnam Construction Joint Stock Corporation's (PVC), Trinh Xuan Thanh, already serving a life sentence, got an additional 10 years in prison for construction investment violations causing serious consequences and eight years for abusing his position and power. The latest sentences will become part of the life imprisonment, the court said.

The court also imposed various jail terms on 10 others, including staff of Petrovietnam Biofuels Joint Stock Company (PVB) - the project investor, PVC - the project contractor and Petrovietnam.

Monday’s ruling ordered 11 offenders to jointly compensate PVB with more than VND543 billion (over $23.5 million). Of this sum, Dinh La Thang’s share is VND200 billion, Trinh Xuan Thanh’s is more than VND143 billion and that of Vu Thanh Ha, former general director of PVB, is VND100 billion.

Thang served as chairman of Petrovietnam between 2006 and 2011, before becoming the Minister of Transport in former Prime Minister Nguyen Tan Dung’s cabinet and then as Party leader of Ho Chi Minh City.

The Phu Tho ethanol plant in the eponymous province is one of three Petrovietnam projects to produce ethanol as material for making biofuel. As approved in Feb. 2009, the project broke ground in Jun. 2009 on a 50 hectare (124 acres) plot with an investment of VND1.3 trillion ($56.36 million).

The court noted that under Thang's instruction, PVB, which was established by the end of 2007 to be the project investor, appointed PVC as the contractor directly, instead of launching a bidding process as required by law.

It said PVC was involved in the project without having any prior relevant experience and it had financial woes at the time. Thang, as chairman of Petrovietnam, directed the appointment of PVC as contractor.

The project remains incomplete as PVC has stopped working on the plant since November 2011.

The court said PVB incurred losses of over VND543 billion ($23.55 million) because of the violations, and that was the sum it must pay banks.

The previous days, Thang had insisted at the court many times that he had not exerted any influence in appointing the contractor.

Thang is already serving a combined prison term of 30 years, the maximum allowed under Vietnam's Penal Code, after he was found guilty in separate trials of economic management violations causing losses of millions of dollars.

He was arrested in December 2017 after being fired from his position as HCMC's Party chief and voted out of the Politburo, the Party’s decision-making body, in a move that analysts called "unprecedented." Thang has also been expelled from the Communist Party.