The brother of murdered Leeds businessman John Luper has made an emotional plea for information on the 20-year anniversary of his death.

Mr Luper was 57 years old when he was killed during a robbery at his home in Sandmoor Drive, Alwoodley, on February 16, 2004.

Specialist ‘cold case’ detectives from West Yorkshire Police’s Major Investigation Review Team are continuing to investigate the unsolved murder.

There is a particular focus on advances in forensic science that could bring new lines of enquiry from existing evidential material.

Mr Luper was attacked by a group of four or five masked intruders as he walked his dog near his neighbour’s driveway at about 11.30pm, before being dragged back to his home. 

His wife, daughter and the family’s au pair were tied up with duct tape and left in an upstairs bedroom until the suspects eventually left the property.

When they managed to free themselves, they found Mr Luper unconscious on the morning room floor. 

Police were called at 1.45am and despite attempts to resuscitate him he was pronounced dead at the scene. A post-mortem examination showed he died as a result of asphyxiation. 

Jewellery and cash totalling around £100,000 were taken during the robbery.

Among the pieces of jewellery was a rare Cartier watch that was platinum with vertical rows of diamonds either side of the face.

Senior investigating officer, Detective Chief Inspector Damian Roebuck, said: “The devastating effects of what happened 20 years ago are still heartfelt with the family of John Luper.

“He was a prominent businessman in the North Leeds area. I would urge anyone who, around February or January 2004, knew of persons making inquiries into him and his business dealings to come forward with names.

“We are committed at West Yorkshire Police to finding those responsible. We know that these attackers made demands for cash and jewellery. Were you actually approached and asked to buy jewellery from unknown people or people you know who didn't actually have provenance or receipts for that jewellery?

“After 20 years our allegiances change and misguided loyalty subsides. It's now time to come forward with an actual name or names of the people responsible for such a horrible crime.”

Anyone with specific information that could assist the investigation is asked to contact West Yorkshire Police's Major Investigation Review Team via 101 quoting Operation Ashkirk or online at www.westyorkshire.police.uk/livechat

Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.