Detectives probing the brutal murder of a London restaurant owner are set to return to Bradford where they are focusing their inquiry.

Officers are keen to trace a group of Bradford 'businessmen' seen in a club with Tahir Butt the night before he was killed, saying they may hold the key to the murder.

They also said it is thought Mr Butt had established links within the city's Asian community and appealed for anyone who knew him to come forward.

Last month, officers from the Metropolitan Police's Serious Crime Group interviewed a number of people in Bradford and distributed appeal posters at police stations and community groups.

A Metropolitan Police spokesman said: "We cannot release the specific details of their inquiries but they spoke to a number of individuals."

He said various leads were still being probed and it was likely that officers would return again.

Tahir Butt's severely beaten and strangled body was found in his burning Mitsubishi Pajero 4x4 on March 17, 1999, at Bushey, Hertfordshire.

Police have revealed that while Mr Butt ran a restaurant in the Wembley area of London, he also had links with Asian organised crime and promoted a troupe of Mudra dancers - an illicit form of entertainment often tied with prostitution.

On the night before the killing, he was in the New Light Club, next to Wembley stadium, where they were performing.

There, he argued with a group of Bradford 'businessmen' who police believe are likely to be involved in criminal activity.

The police spokesman said: "We are still appealing for information about the murder, the incident the night before and the men we are tracing. A £10,000 reward has been offered for information leading to a conviction."

The man seen arguing with Mr Butt is described as being Asian 6ft 1ins, aged about 30 and of chubby build.

Anyone with information should contact the Metropolitan Serious Crime Group on 020 83581755 or Crimestoppers on 0800 555 111.