The former Minister of Industry and Trade is being probed for "violating regulations on management and use of state assets, causing loss and waste."

Ho Thi Kim Thoa, a deputy minister under him, is also being investigated, and the two are detained at home.

Phan Chi Dung, former head of the Light Industry Department at the ministry, was arrested on Thursday under the same charge.

They are suspected to be involved in the mismanagement of a land plot of 6,000 square meters in downtown Ho Chi Minh City. The plot, which was estimated to value hundreds of millions of dollars, has become private property after several illegal transfers.

Hoang was the industry minister from 2007 to 2016 and a part of Prime Minister Nguyen Tan Dung’s Cabinet.

In 2016 suspicions emerged that he had used his political clout to help his son quickly climb the corporate ladder.

In 2011, when Vu Quang Hai, his son, was 25 years old and with no experience in managing a business, he was appointed general manager of PetroVietnam Trade Union Finance Investment Corporation (PVFI).

State-owned PetroVietnam, which is under the Ministry of Industry and Trade, holds a 51 percent stake in PVFI, which has charter capital of more than VND300 billion ($12.95 million).

During the two years when Hai was in charge, PVFI incurred losses of more than VND220 billion ($9.5 million).

Hai was transferred to the industry ministry’s Trade Promotion Agency, and PVFI was on the brink of bankruptcy.

In 2015 he was appointed deputy general director and a board member representing the government’s interests at the Saigon Beer, Beverage and Alcohol Corporation (Sabeco) in HCMC, the country’s largest brewer.

Thoa was directly responsible for his appointment at Sabeco.

According to the Central Inspection Commission of the Party’s Central Committee, Thoa was also guilty of several wrongdoings in the process of equitizing state-owned firms and land management.

It found her responsible for wrongdoings at Dien Quang Lamp, a state-owned firm that was privatized in 2005.

In August 2017 she was removed as deputy minister after seven years at the job.

According to the commission, under Hoang and Thoa, the Party Committee at the industry ministry had acted irresponsibly and violated a number of party and state regulations on personnel in appointing Trinh Xuan Thanh, who did not meet the job requirements, and other officials without following rules or procedures.

Thanh was named deputy chief of office and head of the ministry’s office in Da Nang, and chief of office of the Party delegation at the ministry.

Thanh himself was sentenced to life imprisonment in 2018 in two separate trials after being found guilty of embezzlement and deliberately violating state regulations on economic management, causing serious consequences.