Detectives have re-issued an appeal for information about the unsolved murder of a Jewish man in Leeds.

On the 11th anniversary of John Luper’s death, West Yorkshire Police said they were as determined as ever to get justice for his family.

John Luper, who was 57, died following a robbery at his home on February 17, 2004.

Police believe he was attacked by a group of up to five masked men as he walked his dog before being dragged back to his Sandmoor Drive property in Alwoodley.

His wife, daughter and au pair were tied up by the robbers, who fled with £100,000 worth of cash and jewellery.

Police have long believed that local criminals know who killed Mr Luper because the incident became notorious in the city’s gangland circles.

Mr Luper’s rare diamond-encrusted Cartier watch – one of only four ever sold in Britain – was stolen during the raid.

Detective Superintendent Simon Atkinson, who is leading the investigation, said: “We are continuing to actively investigate his murder and this includes forensic work that could help us to identify those responsible.

“The scientific techniques available to us are developing all the time and we remain hopeful that they will yet provide us with the evidence we need.

“We are convinced that there are people out there who have the information we need to know about who was responsible.

“It is likely that those answers lie within the criminal fraternity who will have been aware of the murder at the time and will have discussed it over the years.

“Allegiances often change over the years and it may be that people are in a better position now to come forward and tell us what they know.”

Anyone with information is asked to contact West Yorkshire Police's Homicide and Major Enquiry Team via 101. Information can also be passed anonymously to Crimestoppers on 0800 555 111.