Former police officer Gerhardus Du Plessis is a State witness in the Henning murder case. His wife has been arrested on drug-related charges, Beeld newspaper reported on Monday. File photo: Etienne Creux

Johannesburg - The wife of a former policeman convicted of the murder of Chanelle Henning has been arrested on drug-related charges, Beeld newspaper reported on Monday.

Lynette du Plessis, 29, was arrested on Sunday morning, said Warrant Officer Hammies Hamilton.

He said police raided a room where Du Plessis and a friend, Chaurn Swanepoel, 23, were staying near Bon Accord dam in the north of Pretoria.

The pair would appear in the Pretoria North Magistrate's Court on Monday.

Police allegedly found used packets of Cat in the room.

Before arresting the pair, the police first had to move Du Plessis' two children to the neighbours. The children were then placed with other family members.

Du Plessis' husband, Gerhardus, is a State witness in the Henning murder case.

He admitted to killing her in November 2011.

Gerhardus testified in court that he killed her for money and drugs. - Sapa