The murder of 17-year-old Marcel Addai shines a light on a bizarre world that sees gangs use professionally produced rap videos posted on YouTube to taunt each other – threats the judge said were “at the heart” of the attack.

Jurors at the Old Bailey were shown eight videos as evidence during the nine-week trial, in which the Hoxton Boys gang and the Fellows Court gang made open or veiled threats to each other.

Most of the videos are still online, and YouTube is coming under mounting pressure to ban them, with MP Meg Hillier vowing hold their “feet to the fire” to “keep on top” of the clips that incite violence.

Several of the videos featured Sodiq Adebayo, 23, and Rickell Rogers, 21, better known by their street names Dirty Crooks and Dubsy, both from in the Fellows Court gang.

Rogers, of Goldney Road, Maida Vale; Adebayo, of De Vere Gardens, Ilford; and Sheku Jalloh, 23, of Crondall Court, St John’s Estate were sentenced to 25 years for murder yesterday, after being found guilty by a jury’s majority verdict of 11 to 1.

Momar Faye, 18, of no fixed address, was sentenced to 22 years in prison after he was found guilty of murder by a majority verdict of 10-2.

One of the videos shown as evidence during the trial, produced by “PacmanTV” – a former cameraman and editor from ITN – sees Rogers lighting up what looks like a joint, saying: “Don’t act like you don’t see me, I’ve been lurking, been on the gully.

“I still needs sweets for that 10 ting, bang. I’ll come round and rally up yer bredren.

“I attempted but I never meant it, I should have ******* ended it. I’m the ‘E2 legend’.”

On Tuesday, as she sentenced Rogers, Adebayo, Jalloh and Faye to life imprisonment, Judge Poulet said: “You travelled in three cars to what you well knew was Hoxton Boy territory. The scene of the attack at which Marcel was killed was the very location of the last video put out by the Hoxton boys in July 2015 threatening the life of Dudsy, that is to say Rikell Rogers.

“Rikell Rogers, you featured in almost all the gang videos, and I have no doubt the ongoing threats between you and the Hoxton boys were at the heart of this attack.”

The barrister representing Rogers said he had actually been hoping to turn his life around through rapping, which he had hoped to pursue professionally.

“Rapping, which became such a feature of this case, gave Mr Rogers the belief he could escape, that he had some talent, that he could become a success in that field,” he said.

“My Lady may take the view that was perverted, that he chose such a subject about which to rap, but one talks about what one knows and it’s a vicious circle.”

Chillingly, just weeks before the killing, Rogers, who called himself an “E2 legend” on Twitter, had posted a tweet stating: “This road ting gonna end one day, they say the only way out is jail or dead and I see both.”

Sentencing them, Her Honour Judge Poulet told Rogers: “And so the gang life proved to be for you, the others in the dock, and your young victim.

“These shocking words capture the tragedy and futility of this way of life.

“Your conduct since your arrests and throughout this trial has shown a ruthlessness, as well as a complete lack of remorse, a cruel disregard of the pain Marcel undoubtedly suffered that night and the continuing anguish of his family.”

Meg Hillier, MP for Hackney South and Shoreditch, had not come across the gang rap videos until this week, and is shocked.

She said: “Given that the young man is dead, it’s chilling – it’s about young people openly and shamelessly intimidating other young people so brazenly that they don’t mind posting it in an international presence. You and I might not look at this but it’s targeted and it might be intimidating to certain people in the neighbourhood.”

In a statement, YouTube, which is owned by Google, said: “YouTube has clear policies that prohibit content like gratuitous violence, hate speech and incitement to commit violent acts.

“The videos are removed when they breach our community guidelines or local laws.”