The two former ministers were arrested in February for violations relating to management and use of public capital.

Cao Duy Hai and Le Nam Tra, former directors of Vietnam’s third largest telecom firm MobiFone, will also be investigated for receiving bribes. Both are already in police custody. Hai was arrested last November and Tra in July for "violating regulations on the management and use of public capital, causing serious consequences."

Also on Friday, police issued an arrest warrant for Pham Nhat Vu, chairman of private pay TV firm Audio Visual Global JSC (AVG), for giving bribes.

The decisions are part of an ongoing investigation into violations in managing and using state investment capital involving MobiFone and certain divisions of the Ministry of Public Security, which has made headlines since 2016.

The nexus came to light after the state-run MobiFone broke into the pay TV market with the acquisition of a 95 percent stake in AVG in 2016.

But government inspectors concluded that the deal had violated public investment laws and caused an estimated loss of about VND7 trillion ($307 million) to the state budget.

Son, then serving as the information minister, directly approved MobiFone's acquisition of AVG against regulations and asked subordinates to sign documents in contravention of regulations, investigation found.

As a deputy information minister from 2011 to 2016, Tuan had signed a decision to approve the acquisition without the Prime Minister’s approval.

Several other officials involved in the MobiFone case were also arrested and are facing criminal charges, including Cao Duy Hai, former general director of MobiFone; Pham Thi Phuong Anh, the firm's former deputy general director; Le Nam Tra, 57, its former chairman and general director; and Pham Dinh Trong, 48, former head of the Department of Enterprise Management under the Ministry of Information and Communications.

An ongoing corruption crackdown spearheaded by Party General Secretary and President Nguyen Phu Trong has seen scores of officials and top businesspeople arrested and sent to jail in recent years. Trong has said that there will be no let up in the anti-corruption drive.