A BUSINESS tycoon who died during a raid on his north Leeds home may have been killed by a powerful electric stun gun.
Detectives investigating the fatal raid on John Luper's £900,000 luxury home at Alwoodley believe this could explain why a post-mortem on the 57-year-old was inconclusive.
Police have been puzzled as to how a gang managed to subdue the 6ft, 16-stone millionaire without any signs of violence.
The raiders escaped with over £100,000 worth of jewellery and cash from his home after tying up Mr Luper's wife, Iyician, daughter Liza Rose, 20, and their au pair, using silver duct tape.
Detectives have said Mr Luper was instantly disabled after being attacked outside his home as he walked his Jack Russell dog late at night.
There are two types of stun guns which they believe could have been involved.
One is pressed against a person and delivers a high-voltage stunning shock and another fires a probe which carries a powerful electrical pulse into the body.
Murder Squad detectives are investigating the possibility that one of the two types was used.
They plan to examine Mr Luper's body for the tell-tale pinprick marks left by the second type of stun gun.
A second theory also being looked at is that one of the attackers rendered him incapable by grabbing him by a pressure point, copying a technique used in martial arts and the military.
Det Supt Bill Shackleton said: "John Luper died because these men decided to commit a very serious criminal offence. They knew there were three women in the house and it was necessary to deal first with the man - Mr Luper - who was outside."