Detectives appealing for information over the murder of Josh Hanson at a bar in Eastcote, Hillingdon, have launched a national manhunt.
Shane O’Brien, 27, of Ladbroke Grove, is being sought by investigating officers who need to urgently speak to him.
Officers say although he has links to the Ruislip area, he could be anywhere in the country.
Detective Chief Inspector Noel McHugh, of the Homicide and Major Crime Command, said: “We are very keen to speak to Shane O’Brien as part of our ongoing enquiries and we believe he could be anywhere in the UK.
“I would appeal directly to Shane to contact us, or ask that anyone who has seen him or who knows where he is to contact us as well. I do believe someone out there will know where he is.”
Shane is described as a white man, 6ft and of muscular build. He should not be approached by members of the public. Any sightings of him should be reported to police immediately on 999.
Anyone with information about his whereabouts can call the incident room on 020 8785 8099 or contact Crimestoppers anonymously on 0800 555 111 or via www.crimestoppers-uk.org.
Mr Hanson, 21, of Kingsbury died after an incident at the RE Bar in Field End Road, Eastcote, Hillingdon, at approximately 01:10hrs on Sunday, 11 October.
Officers and London Ambulance Service attended and Mr Hanson was found suffering a serious wound to the neck. He was pronounced dead at the scene.
DCI McHugh added: “We have had a positive response to our appeal but are still asking anyone who was in the RE bar between midnight and the time of the incident and has not yet contacted us to get in touch.”
Talking previously about Josh, DCI McHugh said: “Josh was a hard-working young lad, up at 5am for his job as a roads planner and often working seven days a week. He had everything to live for and when he went out that Saturday night, no one could have imagined what would happen to him. His family is in pieces.”
Any witnesses or anyone with information should also call the incident room or Crimestoppers.
There have been no arrests at present and enquiries continue.