The Independent Police Investigative Directorate (Ipid) is investigating the death of a civilian in police custody, allegedly at the hands of police officers on Sunday.

Ipid spokesperson Moses Dlamini said two constables from Katlehong North police station stopped a Toyota Verso with six family members. They believed the driver was intoxicated.

"It is alleged that when the police officers tried to arrest the driver, he resisted. Backup was called and other police vehicles arrived. The driver was arrested and several passengers were taken to Katlehong North police station," Dlamini said.

"It is alleged that three men were assaulted at the back of the police station by at least five police officers. After the assault, the three victims were put in the back of the police van and taken to Thelle Mogoerane hospital to draw blood from the driver."

Police officers took the driver to a doctor while two male passengers were left in the back of a police van.

"One male died in the back of the police van and was certified dead by a doctor. There were no visible injuries."

Dlamini said the Germiston mortuary would perform a postmortem.

The driver was later arrested for drunk driving and one other occupant of his car for interfering with the police.

The investigation continues. No arrests have been made.