Khalid Safi, 18 was found with stab wounds after a reported fight in Victoria Road, near the University of the Arts halls, at around 6.30pm on 1 December 2016.
He was rushed to hospital from the scene but died from his injuries a short time later.
A post-mortem examination showed that Khalid died from a stab wound to the heart.
Police want to speak to 19-year-old Raza Khan in connection with Khalid's death and are offering £5,000 for information about the fatal stabbing.
On Friday (December 1), the one-year anniversary of the killing, Metropolitan Police made a fresh appeal to find Khan.
According to police, Khan is likely to have remained in the UK and is known to have links to Acton, Wembley, Ilford, Friern Barnet and Tottenham and also to Dover in Kent.
Khalid's brother Shamsullah Safi said: "It has been one year since Khalid was killed and I have not forgotten my brother for a single minute.
"I want the attacker to be brought justice as soon as possible. My brother's death has completely ruined my life.
"My brother was very young, only 19 years old when he was killed in the street.
"He came to London for a better life but was killed for no reason. I want to appeal to anyone, especially the Afghan community who has any information to come forward and speak to the police."
Detective Chief Inspector Sam Price, who is leading the investigation for the Homicide and Major Crime Command, said: "One year on from Khalid's murder we continue to seek the whereabouts of Raza Khan, 19, who is wanted for questioning by police in connection with the killing.
"Similarly, with the passing of 12 months, I am hoping that witnesses who may have been hesitant to come forward at the time may now feel able to speak with officers.
"In addition, anyone providing information anonymously via the independent charity Crimestoppers could be eligible for a reward of up to £5,000."
He added: "We are particularly keen to trace Raza Khan who we believe has crucial information about what happened to Khalid."
Anyone with information should call police on 020 8721 4054.
To give information anonymously contact the charity Crimestoppers on 0800 555 111 or visit www.crimestoppers-uk.org.
A reward of up to £5,000 is being offered for information given to the charity that leads to the arrest of Khan .
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