One of the alleged killers of teenager Marcel Addai wrote a “stupid” letter to a co-defendant while in prison containing false evidence for him to use, a court has heard.

Sheku Jalloh, 23, of Crondall Court on the St John’s estate, said he wrote Eugene Ocran an account of the night of Mr Addai’s fatal stabbing after Ocran asked him what to say while awaiting trial.

Seven men deny murdering the 18-year-old in Pitfield Street, Hoxton, on September 4 last year. They are Sodiq Adebayo, 23, of De Vere Gardens, Ilford; Akeem Gbadamosi, 22, of Detmold Road, Clapton; Ocran, 19, of Fermain Court West, De Beauvoir Road, Haggerston; David Oladimeji, 21, of Axon Place, Ilford; Rikell Rogers, 22, of Goldney Road, Maida Vale; and Jalloh.

Mr Addai, who lived nearby in Wenlock House, Evelyn Walk, was allegedly chased and stabbed 12 times. He was a member of the Hoxton Boys gang, who prosecutors say had a fierce rivalry with the Fellows Court gang, of which six defendants were members.

Under cross-examination at the Old Bailey yesterday Jalloh said he realised the letter was “stupid” and was written to help him, Ocran and Faye, by saying nobody had got out of a BMW spotted at the scene, which they were in.

He now says only Faye got out of the car after hearing a bottle smash. “I didn’t look,” he said. “I just said ‘get me out of here’.”

Witnesses allegedly saw a number of people get out of three cars the seven men had travelled to the area in. Ocran’s lawyer Stephen Kamlish played jurors CCTV of what he said was the killing, in which screaming can be heard. Jalloh said he didn’t want to be in the area because he wasn’t allowed there but Oladimeji was getting cash from his mum’s home.

Mr Kamlish said: “As David Oladimeji returned to the car a bottle was thrown in his direction by a group including Marcel Addai. [...] You, Rogers and Adebayo joined David in an attack on Marcel Addai who had been left by his friends.” Jalloh: “I didn’t get out of the car and I didn’t stab him.”

Mr Kamlish also quizzed Jalloh about a “furious attack” in the Belmarsh Prison chapel on Sunday, accusing him and Adebayo of “sending a message” to Ocran and Faye by assaulting someone from the gang they had links to. Jalloh said he was targeted in the fight.