Detectives have appealed to Bradford’s criminal fraternity for help in the hunt for the brutal killers of a West Yorkshire businessman.

John Luper, 57, was murdered ten years ago during a robbery at his home.

He was attacked by a gang of four or five masked men as he walked his dog, and dragged back to his house in Sandmoor Drive, Alwoodley, Leeds.

His wife, daughter and the family’s au pair were tied up with ducting tape and left in a bedroom. They freed themselves and found Mr Luper, a clothing tycoon who was diabetic, unconscious on the kitchen floor. He had been asphyxiated. The suspects fled the property with jewellery, cash and clothes worth £100,000.

Detectives said they believed professional criminals from Bradford and Liversedge, involved in robbery and organised drug-dealing, could have been responsible.

Farm buildings and land on the Windybank estate at LIversedge were sealed off and searched for two days ten months after the murder.

Several arrests were made earlier in the inquiry, but no-one was charged.

Among the gems stolen was a Cartier platinum watch, with vertical rows of diamonds on either side of the face, which was one of only four sold in the UK at the time. Officers are still keen to hear from anyone who may have been offered such a watch for sale.

Detective Chief Inspector Simon Atkinson said: “We would like the people of Bradford to look at the picture of the watch and consider whether they have seen it or been offered it.

“We are looking at connections with the criminal fraternity of West Yorkshire, including Bradford. We cannot rule out that the perpetrators may be from Bradford, and assistance from people in Bradford will be vital in the inquiry.

“It will have been talked about in Bradford.”

Det Chief Insp Atkinson said forensic work was still being carried out which may yet yield important evidence to pinpoint those responsible.

He added: “We have received some very useful information from people over the years but we are convinced there are others out there with more to say.

“With the passage of time, certain allegiances may have changed and people may now be in a better position to come forward and assist us.

“I would urge anyone who has such knowledge or was perhaps on the periphery of this incident to contact us.”

Anyone with information is asked to contact West Yorkshire Police’s Protective Services (Crime) via 101, or Crimestoppers, anonymously, on 0800 555 111.