Detectives investigating the killing of Jonathon “JJ” McPhillips in Upper Street have made a fourth arrest.

A 21-year-old man was arrested yesterday on suspicion of murder. He has been taken to an east London police station for questioning.

Detectives have already made three arrests in the hunt for his killer. On March 4 a 24-year-old man was arrested on suspicion of murder. He was bailed until mid-April.

A 19-year-old man was arrested on March 16 on suspicion of murder – he has been bailed until mid-June. And the same day a woman, 45, was arrested on suspicion of assisting an offender and has been bailed until early May.

JJ was stabbed in Upper Street in the early hours of Saturday February 25, and died the following Wednesday.

The father-of-two reportedly stepped in when a gang picked a fight with his friends but was knifed along with a 17-year-old boy, who suffered minor injuries.

A post-mortem gave his cause of death as single stab wound to the chest.

The Homicide and Major Crime Command (HMCC) led by Det Ch Insp Dave Whellams are investigating.

Anyone with information can call police on 020 8345 3775, or Crimestoppers anonymously on 0800 555 111.

Enquiries continue.