Mr Clarke's body was discovered by his teenage stepson

They were seen running along Moorland Avenue in the early hours of Thursday and police want to eliminated them from the investigation.

The body of Richard Clarke, 32, was discovered by his 14-year-old stepson at his Moorland Avenue home.

He had been shot in the head but there were no signs of any forced entry.

Det Supt Steve Fear said Mr Clarke, who was already known to police, was the victim of a "brutal murder".

'Exceptionally dangerous'

He said the victim was killed by a single gunshot wound to his head as he slept next to his girlfriend.

She is believed not to have heard anything until one of her children came into the living room and raised the alarm.

Officers have spoken to more than 300 residents so far and house-to-house inquiries continue.

Remnants left at the scene continue to be examined by forensics and ballistics experts.

Mr Fear said: "We have carried out detailed searches of nearby dustbins and drains in a bid to locate the weapon used to kill Richard Clarke and will be widening the net further.

"At least one exceptionally dangerous individual is responsible for shooting Richard Clarke dead at point blank range in the presence of his partner."

He said there had been a positive response to the murder investigation from both the general public and the criminal fraternity and "a number of possible leads" were being followed up.