Detectives investigating the murder of a lawyer who was stabbed with a screwdriver have made a further arrest.

Peter Duncan, 52, sustained a fatal chest wound after becoming involved in what police described as a chance encounter.

Northumbria police arrested seven boys aged 14 to 17 on suspicion of murder. Four of them, two aged 15 and two aged 17, have been released with no further action taken, and the 14-year-old has been released under investigation.

Two 17-year-olds remained in custody and a 15-year-old has now been arrested in relation to the incident.

The teenagers were arrested after the fight in front of shoppers in Eldon Square mall at 6.20pm on Wednesday.

Duncan, a lawyer for the maritime services company Royal IHC, was taken to Royal Victoria hospital where he later died.

On Friday Duncan’s family paid tribute to a man who was “loved by all who knew him”.

They said: “Peter was a kind and caring man who was always first to help others. He was a devoted father, husband, son, brother, uncle and friend and loved by all who knew him.

“His death will leave such a huge hole in our lives and he’ll be deeply missed by us all. Words can’t quite describe what life will be like without him. He had so much of his life left to live and he’ll be in our hearts and thoughts every day.”

According to his LinkedIn profile, Duncan was an electrical engineer before training as a solicitor at Northumbria University in 2003. He worked in Newcastle for Royal IHC, which has a city centre office close to where he was attacked.

Northumbria police said the investigation was at an early stage but it appeared there had been a “coming together” at the entrance to the shopping centre.

The Northumbria police area commander, Ch Supt Ged Noble, said: “This was a tragic incident and our thoughts go out to Peter‘s family and friends at this incredibly difficult time. They continue to be given any support they may need by a team of specialist officers. Peter’s family have requested that their privacy is respected during this difficult time.

“I appreciate the communities we serve will have concerns, and I want to reassure the public and businesses that we are doing all we can to prevent incidents of this tragic nature and ensure people feel safe.

“We will be continuing extra patrols in the area and I would urge anyone with concerns to speak to an officer. We are committed to finding out the circumstances behind Peter’s death, and I’d like to thank members of the public who’ve been in touch passing on information that could assist detectives with this investigation.

“Our inquiries will continue and I would ask anyone who witnessed the incident, who are yet to come forward, to pick up the phone and contact police.”

He praised the public for attempting to help the victim after he had been fatally injured, as well as for providing information to police.