Former Bosasa COO Angelo Agrizzi and former correctional services commissioner Linda Mti are among those arrested by the Hawks on allegations of corruption related to the facilities management company.

The Hawks on Wednesday said six suspects had been arrested - with a warrant of arrest issued for a seventh - on allegations of corruption, money laundering and fraud.

The arrests also includes former correctional services CFO Patrick Gillingham, Bosasa official Andries van Tonder, and three companies, namely: African Global Operations (formerly Bosasa); Sondolo IT and Phezulu Fencing, according to court papers.

Five of the suspects are due to appear in court on Wednesday, while a sixth is being transferred from Port Elizabeth. The seventh is overseas, and has been informed of his warrant of arrest.

Earlier on Wednesday, Hawks spokesperson Brigadier Hangwani Mulaudzi said the suspects were between the ages of 50 and 78.

"The sweeping high-profile arrests follows a marathon investigation wherein almost R1.6-billion is said to have been misappropriated in the tender processes for the procurement of various services by the Department of Correctional Services," Mulaudzi said.

"The tenders were awarded to Bosasa Operations (Pty) Ltd and its affiliated or subsidiary companies."

Mulaudzi said it was alleged that the officials received and accepted gifts in the form of cash. They also allegedly received financial assistance with acquiring properties, acquiring motor vehicles from dealers, other assets and payments to travel agents for overseas travel.

"One of the suspects is overseas. However, he has been informed that there is a warrant for his arrest."

Another suspect had been arrested in Port Elizabeth and was being taken to Pretoria to face the charges.

The State capture inquiry has heard damning testimony over the past three weeks related to corruption in the prison services sector, dating back to the late 2000s.

Hawks head Lieutenant General Godfrey Lebeya welcomed the arrests.

"I appreciate that the attendance of the accused in court is finally secured. It is a step in the right direction and am looking forward to proper conclusion of the matter with a verdict in court," said Lebeya.

Five of the original suspects, including three companies, are expected to appear at the Pretoria Specialised Commercial Court on Wednesday.