Footage from a camera at a posh Cape Town restaurant recorded a private meeting between the care home tycoon and driver Zola Tongo after wife Anni's death.
The film and examinations of phone call and text records prompted South African authorities to launch moves to extradite Dewani, The Sun states.
A police source in Cape Town, where the honeymooning couple's taxi was ambushed in a crime-ridden township last month, said: "Tongo's claim he was given money by Dewani after Anni's death is backed up in full colour on video. CCTV footage shows them meeting in a restaurant area of a hotel and Shrien Dewani hands money to the driver.
"This was days after Anni's body was found, at a time when Dewani was staying in the Cape Grace Hotel and being comforted by relatives.
"Police believe they have enough evidence to prosecute Dewani and that there is a clear case to answer."
It was unclear why the businessman handed over the money - and whether he was simply paying a fare.
A source close to him said: "This may be one of many instances where the wrong conclusions are being drawn and two plus two is being made to equal five."