Detectives investigating the fatal stabbing of 18-year-old Ahmed Yasin-Ali are trying to trace a car they believe was used in the murder.
The teenager was heard begging “No, no, don’t do this” as he was ambushed and beaten by a gang in Maida Hill in the early hours of July 15.
On Sunday officers released two images showing a blue Mazda 2 GT Sport displaying cloned number plates with the registration LD17CXS.
The car had been given a parking ticket on the Barrow Hill Estate, St John’s Wood, five days before the murder.
A third image shows the same car at 12.28am on July 15 in Woodfield Road, minutes before the murder in nearby Elmfield Way. The car has not yet been recovered.
Detective Chief Inspector Vicky Tunstall, said: “Mazda 2 GT Sport cars are relatively uncommon as a make and model in this colour.
“I am appealing to anyone who is involved in the motor industry, for example, who has bought or sold such a vehicle recently to get in touch. It is critical that we trace this vehicle as soon as possible.
“Similarly, if any member of the public has recently bought or sold a Mazda GT Sport in this colour, I need to hear from you.
“This car was involved in the death of a young man whose life was taken in a tragic and unnecessary way. Finding this car will be key to our investigation and my team will leave no stone unturned in their efforts to find it.
“Have you seen a vehicle liked this parked in a car park or in a street? Regardless of its registration, please get in touch.
“Has anyone asked you to use their garage or lock up recently and, if so, was it used to store a car?
“No matter how unimportant you think your information might be, please don’t hesitate, what you know may in fact be a vital piece of information. Tell us what you know and leave the rest to us.”
Three men in their twenties and a boy, 17, have been arrested in connection with the murder and released on bail to a date in August.
Anyone with information is asked to call police via 101 or Tweet @MetCC quoting 185/15Jul. To remain 100% anonymous, call the independent charity Crimestoppers on 0800 555 111.