Wealthy businessman Shrien Dewani, 30, was released from Wandsworth Prison on bail on Friday after his family came up with 250,000 security. The care home owner is wanted by South African police for conspiracy to murder his new wife Anni, 28.
National Commissioner General Bheki Cele said yesterday police are now investigating a link between Dewani and the 2007 murder of Dr Pox Raghavjee.
Media reports suggested the Eastern Cape doctor's widow knew Dewani and drove to Cape town to comfort him on the death of his wife.
Cele's spokeswoman said yesterday: "The investigation is ongoing even if it means linking Mr Dewani to other cases."
Publicist Max Clifford, who is representing Dewani, said: "It's a great story but it's a total fabrication. How flimsy and ridiculous this whole thing is.. Anni's father and Shrien's own father were both there with him after the murder. I'm sure a woman turning up to comfort him would not have been much appreciated and would have been mentioned by Anni's father."
Despite pleas by prosecutors at the High Court on Friday to keep him on remand, Dewani, from Westbury-on-Trym, Bristol, was granted bail and now faces electronic tagging, home curfew and daily reports to the police pending further extradition hearings.
Dewani's wife was found dead in the back of an abandoned taxi in a Cape Town township with a single bullet wound to her neck on 13 November.
Dewani was arrested this week after the South African authorities issued a warrant. The warrant came after taxi driver Zola Tongo accused him of offering to pay 15,000 rand (1,400) for his wife's murder and ordering it to appear like a bungled carjacking as they drove through the notorious township of Gugulethu.
Tongo's allegation formed part of a plea agreement with prosecutors at Western Cape High Court, where he was jailed for 18 years earlier this week for his part in the killing.