GQ magazine has named him as Harry Uzoka, a model who had recently done a photo shoot for them.
Friends and fans, including fellow models and a singer, have paid tribute to Mr Uzoka, describing him as an “inspiration to young black men”.
Two men aged 27 and 28 were arrested near to the scene on suspicion of murder, and are in custody.
Police think the incident started at Ollgar House, in Ollgar Close, and that Mr Uzoka was assaulted and stabbed before staggering and collapsing in Old Oak Road.
Det Insp Kofi added: “We believe there were a number of people involved, but we are still working to establish the circumstances and a possible motive.”
It is the fifth murder investigation under way in London this year, four of which have been fatal stabbings.
A GQ reporter said: “The staff of GQ are appalled and saddened by his death and would like his family to know that our thoughts and prayers are with him and his loved ones.”
Fan Lew Bloyce, 22, has followed the young model’s blossoming career.
The Selfridges employee from south-east London said: “I’ve known of him for many years via social media.
“I’ve always looked at him as an inspiration to young black men and something of an icon.”
‘A great person’
A spokesman for Premier Model Management said its thoughts were with the Uzoka family.
The agency features a portfolio of photographs of Mr Uzoka.
Online clothing retailer Everlane added: “We’re deeply saddened to hear about Harry Uzoka’s passing. He was a wonderful model, but even more so a good person and a pleasure to work with.
“There’s so much more behind the person you’ve seen in our campaigns.
“Thank you, Harry, for being such a great person. Rest in peace.”