Detectives investigating the fatal stabbing of a man in Barnet have released CCTV images of potential witnesses they would like to speak to.

On February 17, police were called to Heathfield Gardens, Brent Cross, following reports of a number of males fighting.

Officers attended and found 21-year-old Joseph Olopo - who was from Colindale - with a stab wound. He was taken by the London Ambulance Service to St Mary's Hospital but was pronounced dead shortly after arrival.

A post-mortem examination held on February 19 gave cause of death as a stab wound to the neck.

Detectives are attempting to identify four people who left Brent Cross Underground Station and were in the Heathfield Gardens area at the time of the stabbing.

Detectives from the Met's Homicide and Major Crime Command are investigating.

Detective Inspector Shaun Fitzgerald said: "We have spoken with a number of people as part of our ongoing investigation into Joseph's murder. However, the two men and two women in the images we have released today are yet to speak with us.

"It is possible that they may believe that they did not witness anything, however any piece of information regardless how minor it may seem, could be important to our inquiry.

"I would urge them to contact the incident room."

Anyone with information is asked to contact the Incident Room number on 020 8358 0100 or Crimestoppers anonymously on 0800 555 111.

Two males were arrested near to the scene on suspicion of affray. One was bailed to a date in April pending further enquiries; and the second was released with no further action.

A 20-year-old man who was arrested on suspicion of violent disorder on February 21 was bailed to a date in April.

A 21-year-old man was charged with murder on February 23.