Detectives have made four arrests in connection with the murder of a Bradford businessman.

Great-grandad and father-of-four Edward Simpson, 56, known as Teddy, was brutally and viciously assaulted in his detached home in Sticker Lane, Laisterdyke, and died of multiple injuries.

His body was dumped 12 hours later in a secluded wooded lane, near the former Shirley Manor residential home, off Huddersfield Road, in Lower Wyke.

The motive for his killing is still unclear.

A West Yorkshire Police spokesman today revealed that the investigation had taken a step forward with the arrest of four people last night.

Two were later released without charge.

But the spokesman said that the force's Homicide and Major Enquiry Team was continuing its investigations.

She said: "We have arrested four people in connection with the inquiry. Two of those arrested have been released without charge.

"We are looking to make more arrests over the weekend."

Mr Simpson was at his home on Wednesday when a number of men burst in, sometime between 7pm and 8pm, and violently assaulted him in the house.

It is thought weapons were used in the attack, although the force spokesman would not confirm whether a gun was used.

His body was found, unconcealed at 8.40am on Thursday, by two Council workmen on the lane leading to the Shirley Manor home, which is now being used as a Bradford Council storage depot.

The spokesman said: "We still need members of the public to come forward and assist us in this investigation into this brutal and vicious assault."

Meanwhile detectives were today continuing to try to fill the gaps of the final 12 hours of Mr Simpson's life.

They want to know what happened following his disappearance and the discovery of his body, and the reason why he was killed.

Detective Superintendent Paul Taylor, of West Yorkshire Police's Homicide and Major Enquiry Team, who is leading the investigation, said: "I don't know the motive for this, but I am sure there are people who do know why it happened.

"This was an absolutely brutal and vicious assault and he did not deserve that. He has a large family and I have met a lot of them and they are very, very distressed. The only thing that will bring them a little bit of comfort is to piece together what has happened. We need to put 100 per cent into detecting the murder, for Teddy and his family."

Mr Simpson lived in a large detached house with his car business premises adjoining it. He also had a stone sales business.

Police admitted he was known to them but declined to go into more details.

Anyone with information about Mr Simpson's murder should contact the HMET incident room on (01274) 373700, or text WYKE, followed by a message, to 07786 200806. People can also call Crimestoppers, anonymously, on 08000 555 111.