Police hunting for a man suspected of murdering a family from Northampton have increased the reward for information which could lead to his arrest to £25,000.
Jifeng Ding, his wife Helen Chui and their two daughters were killed in Wootton on the 29th April 2011 - the day of the Royal Wedding. Anxiang Du, who detectives named as the main suspect, has still not been traced.
At a press conference almost a year on senior detectives from Northamptonshire Police announced that the £10,000 reward put up by Crimestoppers after the murder would be increased.
Detective Chief Inspector Tom Davies said police were "unwavering" in their efforts to find Anxiang Du, and that they "strongly believe" he is still alive.
It was revealed that so far in the investigation they have spoken to 2000 people in connection with the case, and have gone through 5000 hours of CCTV footage. Police say there have also been 380 reported suspect sightings, in countries including France, Spain and Gibralter, but that so far none of them have been confirmed as Anxiang Du.