Ding murders: Crimewatch reveals new CCTV footage
Unseen CCTV footage of a man police suspect of killing four members of a family in Northampton has been released in a new appeal.
Jifeng Ding, his wife Helen and their two daughters, Alice, 12, and Xing, 18, were found stabbed to death at their home in Wootton on 1 May.
The Dings' business partner Anxiang Du, from Coventry, is the prime suspect but has not been seen since May.
The CCTV footage of Mr Du in London was shown on the BBC's Crimewatch.
The footage shows the businessman abandoning the Ding family's silver Vauxhall Corsa car at 02:27 BST on 30 April in Venables Street, off Edgware Road.
It was the last confirmed sighting of the 52-year-old, who is a previous business associate of Mr and Mrs Ding.
Mr Du, who worked at a herbal medicine shop in Birmingham, went missing a day after losing what has been described as a bitter court battle over his shared business interests with the Ding family.
Det Supt Glyn Timmins said there had been 300 possible sightings of Mr Du but they were particularly interested in one in Gibraltar shortly after the murders.
He also said a distinctive footprint had been found at the scene which they believed was from a pair of handmade shoes with unusual soles.
Crimestoppers has previously offered a reward of £10,000 for anyone with information which leads to the arrest and conviction of the person responsible for the murders.