The incident occurred in Athlone on Monday, October 22.
The man, identified as Jean-Pierre du Preez, was allegedly driving drunk in Sea Point when he was arrested and taken to the Sea Point Police Station.
According to a police source, Du Preez’s parents had come to the police station to collect his "things' and left again.
The source says they could not confirm whether Du Preez had any prior cases of drunk driving or if he had had a valid driving licence.
He was loaded into a police van and transported to the Shadow Centre in Athlone for drug testing.
The centre is situated off Jakes Gerwel Drive next to Vangate Mall.
The source says offenders are usually transported to the closest centre for drug or alcohol level tests.
They are then returned to the arresting police station for further processing.
When the officers opened the van to escort Du Preez into the facility, he was allegedly found hanging from the roof.
“He was unresponsive and did not have a pulse.”
The source blames the officers.
“They should have ensured his safety. It is still unclear what he had used to hang himself with, but it appears he was neither searched nor handcuffed before he was placed in the back of the van.
“Anything which would have posed a threat to him, should have been removed,” the officer said.
He adds that Athlone police responded to a call from the officers at the scene.
Police spokesperson Captain FC van Wyk confirms: “A 33-year-old man was arrested on Monday on a charge of drunk driving in Sea Point.
“His death (inquest) is now part of an Ipid investigation.”
Ipid spokesperson, Moses Dlamini, confirms his office is investigating the incident.
“The matter was reported to the Ipid office immediately and our investigators attended the scene,” Dlamini says.