Hani Hicham Abou El Kheir, 16, was killed in Pimlico, one of London’s most affluent areas, on 27 January 2013.
Five men were convicted of his murder and sentenced to a total of 131 years in prison following a trial at the Old Bailey in January 2014.
However, police say one murder suspect remains outstanding and have issued a fresh appeal to the public for information to help locate him.
Dilawar Hussain, now 33, was born in Paddington and raised in London.
Police searched his then home in Rampayne Street, Pimlico, four days after the murder, but he was not there.
Officers obtained an arrest warrant at Barkingside Magistrates’ Court on 21 March 2013 and found that Hussain, who was 21-years-old at the time, had travelled to Bangladesh.
Detective Chief Inspector Mark Rogers, who is leading the investigation, has said officers believe he is still there.
Mother says son was killed by ‘feral men’
The Met Police has said an arrest warrant remains in place for Hussain and “efforts continue to be made” to ensure he “faces justice for Hani’s murder”.
The teenager’s mother Pauline Hickey has also appealed for information related to Hussain’s whereabouts.
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Ms Hickey said: “It is now 12 years since my only son, Hani, was hunted down and attacked in a busy street by a group of feral men. While several people have been jailed for his murder, one suspect remains free.
“Hani was only a boy when he was killed – he had his whole life to live and this was brutally taken away.
“The pain of his loss does not diminish with the passing of time and it only feels greater knowing Dilawar Hussain has evaded justice so far. If you can help, I would plead with you to get in contact with the police.”
DCI Rogers said: “I am appealing for information as to the whereabouts of Dilawar Hussain… Hani’s mother Pauline continues to fight for justice and to ensure those responsible for her son’s murder are held to account, and we will not rest until we’ve helped achieve this for her.”
