The arrest was made Wednesday by investigators at the Ministry of Public Security, spokesperson Major General To An Xo told VnExpress on Friday.

Also on Wednesday, police officers arrested Nguyen Chi Thanh, acting head of the finance department under the Transport Ministry, and Nguyen Trung Cuong, a department official.

The trio, alongside Dinh La Thang, a former political star who used to serve as Transport Minister and chairman of the state-owned oil giant Petrovietnam, are being probed for "violating regulations on management and use of state assets, causing loss and waste." Thang is in jail for violations at Petrovietnam.

Authorities are investigating violations related to bidding and toll collection on HCMC-Trung Luong Expressway, opened to traffic in 2010, and the only expressway connecting HCMC and the Mekong Delta.

Specific details of their wrongdoings have not been revealed.

Truong, 62, served as Deputy Minister of Transport from 2007 until he retired in 2017.

During his tenure, he was assigned to take charge of projects like the upgrade and expansion of major roads passing through the Central Highlands.

In September 2019, Truong was retrospectively stripped of his position as Deputy Transport Minister for the 2011-15 and 2016-17 terms for wrongdoings in the privatization of state-owned firms.

The Communist Party had meted out similar punishments to him in July that year.

Thang, 60, is serving a combined prison term of 30 years, the maximum allowed under Vietnam's Penal Code, after found guilty in two separate trials of economic management violations causing losses of millions of dollars.

A former political kingpin, Thang served as board chairman of Petrovietnam between 2006 and 2011, before his career took off as Transport Minister in former Prime Minister Nguyen Tan Dung’s cabinet, and then as Party leader of Ho Chi Minh City.

Vietnam’s corruption crackdown spearheaded by Party chief and President Nguyen Phu Trong has intensified since it was launched in 2017, with a number of high-ranking officials, top military officers and businesspeople probed and imprisoned.