A British couple was beaten to death in Cape Town, South Africa, by a group with alleged links to Islamic State, several British media outlets report.

According to Notícias ao Minuto on Thursday, Rod Saunders, 74, and his wife Rachel, 63, were known internationally for their work as successful biologists. "The couple had just finished recording an episode for the BBC when they were ambushed in a forest."

After murdering the couple, the group put the bodies in sleeping bags and threw them into a crocodile-infested river. "Beforehand, they stole their credit cards, from which they took 40,000 euros," says the portal.

The bodies have since been found, but it took months for them to be identified by DNA tests.

After having these results, the authorities quickly made the connection between the victims and the suspects and arrested Sayfudeen Aslam Del Vecchio, 41, his wife Bibi Fatima Patel, 30, and their tenant Mussa Ahmed Jackson, 35.

During the search of the suspects' homes, in addition to evidence of the crimes, South African police found Daesh leaflets.

The trio are now on trial for the crimes of kidnapping, robbery and double murder.