Police investigating the stabbing to death of a family of four at their home in Northamptonshire have said that Ding must have been given help to hide.
The bodies of Jifeng Ding, his wife Helen and their two daughters, Alice, 12, and Xing, 18, were found at their home in Wootton on 1 May.
Anxiang Du of Coventry was last seen on CCTV in London on 30 April, the day after the family were killed.
Detectives appealed to anyone who may be helping him to give him up.
‘Looked after’
They said they had no information to suggest Mr Du had fled the country and were working on the premise that he was last seen in London.
Det Ch Insp Tom Davies said: “The lack of positive sightings and the lack of information we’ve had around Anxiang Du suggest to me that he’s been looked after by someone in the community.
“One of my appeals would be for people to bear in mind there is a Crimestoppers reward of £10,000 available.
“We do need to get him off the streets as soon as possible.”
In London’s Chinatown, teams of police officers have been meeting community leaders on Monday handing out leaflets to the local people and businesses.
Specialist officers from the Met Police and London force’s Chinese Unit have been involved in the visit to Chinatown.
Det Ch Insp Davies said of the Chinese community: “The feedback we got was very positive.
“They appreciate the nature of our investigation. They’re very supportive.”
Det Ch Insp Davies also said police were looking at a variety of knives found at various locations and were working with forensic experts to establish which were used in the murders.