Detectives have released CCTV stills of seven people they hope to trace one year on from the murder of a popular Fulham singer in a west London underpass.

Ian Newtion, also known by his stage name Scoobie Santino, was stabbed in the neck by a thug wielding a broken bottle under Greenford Roundabout.

Police are unable to piece together Mr Newtion's last movements in the hour before his death despite offering a £20,000 reward for information and arresting 24 people, all released without charge.

Eldest brother Cleave Newtion, 55, said: "When you're haemorrhaging pain and sorrow you have to find some way of containing it or you couldn't go on.

Until we find closure, that necessity for Ian's family and close friend remains, it's just as raw.

"It's the brutality and nature of the murder as well as the unanswered questions. "There was nothing going on in Ian's life to inform why anyone would wish to end his life."

The 45-year-old reggae singer and lorry driver had been singing at a party in the Scout Hut, Rockware Avenue, Greenford, and was on his way home to Fulham when he was attacked.

He left at 7.45 am on Mother's Day, March 22, and was last seen looking agitated by a jogger ten minutes later. He was wearing dark clothes and a headscarf.

He was found dead at about 8.50am in a tunnel in the underpass.

Police believe the seven people captured by CCTV from a petrol station nearby may hold vital clues.

Cleave Newtion added: "It's absolutely vital people come forward.

"There's no information, nothing enlightening us to why he ended up at that exit of the subway, who he may have spoken to or who may have met him.

"Individuals may think they have to have some comprehensive information answering all these questions but all we need is to start narrowing down the time-line. They may think it is irrelevant information, as to which route he took or whether he was alone, but they are all pieces of information about that critical hour."

Family and friends have not stopped their efforts to find a breakthrough, from setting up social networking sites to making appeals at the murder scene.

There were a number of robberies were a bottle was used as a weapon near the scene, but none of Ian Newtion's property was stolen.

Police believe the killer may have cut his hand in the attack.

They are also asking for a teenage girl seen in the area to come forward. She bought a large hydrangea for her nan from a florists called Making Scents in Greenford Station at about 9am. She is about 5ft 5ins with light hair which was tied back.

DCI Tim Duffield of the Homicide and Serious Crime Command, said: "I would encourage anyone who thinks they have recognised themselves from the CCTV to come forward and speak to police - they may hold information vital to solving this crime but might not have realised the significance of it."

Call the incident room on 020 8358 0400 or Crimestoppers, anonymously, on 0800 555 111.