Officers and paramedics were scrambled to near Dagenham Heath Tube station just before midnight on Friday, following reports of a machete fight between two groups of people.
They found a man - who has now been identified as 18-year-old Jordan Kukabu, from Romford - with stab injuries.
Despite the best efforts of medical professionals he was pronounced dead at the scene.
Scotland Yard says a post-mortem examination held on Sunday, gave Mr Kukabu’s cause of death as a single stab wound to the chest.
A second man, aged 20, was also taken to hospital with a stab injury. His condition was assessed as non life-threatening.
A 20-year-old man was arrested on suspicion of murder, but has been released with no further action. However, he was also arrested on suspicion of violent disorder and has been released on bail for this offence.
It was with great sadness that this afternoon I learned that my nephew, Jordan, 18, had been stabbed to death in Dagenham last night. His mother is inconsolable. If you are gang member, this message is for you. Drop your knife and quit the gangster life before it is too late. pic.twitter.com/7tvpUM5PzN
— Cllr Michel A. Pongo (@m_a_pongo) May 6, 2023
Mr Kukabu’s uncle Michel Pongo said his mother has been left “inconsolable” following her son’s death.
Mr Pongo, who is a councillor for Barking and Dagenham, wrote on Twitter on Saturday: “It was with great sadness that this afternoon I learned that my nephew, Jordan, 18, had been stabbed to death in Dagenham last night.
“His mother is inconsolable. If you are gang member, this message is for you. Drop your knife and quit the gangster life before it is too late.”
Detective Chief Inspector James Shirley, from the Specialist Crime Command, said: “My thoughts remain with the young man’s family and friends. Dedicated detectives have been working around the clock since this tragic incident as we strive to identify and apprehend those responsible for killing Jordan.
“Our investigation is making significant progress. Local people have provided us with information, which together with forensic enquiries and analysis of CCTV is enabling us to build a picture of what happened on Friday night.
“I am grateful to everyone who has provided information. There will be other people with information that would assist our investigation and I urge them to come forward and share what they know or any relevant footage. This can be done anonymously through Crimestoppers should anyone prefer not to speak with police.”
Superintendent Martin Rolston of the Met’s East Area Command Unit, said: “I am well aware of just how much this shocking incident has affected people in Dagenham and the surrounding area. I share their concerns and can assure local people that the Met’s investigation is painstaking and completely focused on getting justice for the family and friends of Jordan.”
Anyone with information should contact police on 101 or tweet @MetCC quoting 8711/05May. To remain 100% anonymous share your information via the independent charity Crimestoppers on 0800 555 111.