The community has reacted with fury after hundreds of leaflets were posted calling for residents not to help police after a Streatham teenager was shot dead.

The flyers, from an organisation called Stop Snitching, were found on the Pelican estate, Peckham, where 17-year-old Sylvester Akapalara was found dead in a stairwell on December 29.

The sporty pupil, who showed great promise as a 400 metre runner, was found with gunshot wounds in his neck and chest, prompting tributes from friends and teachers.

The leaflets were linked to a website urging people not to trust Operation Trident, the Metropolitan Police team that investigates gun crime in London’s black community.

The website said: “Don’t be decived [sic] by promises of anonymity, protection, and rewards. They will say and do anything to make you snitch, then destroy your life.

“We will be able to give you first-hand accounts of how Operation Trident have ruined the lives of witnesses, you will be able to listen to real covert recordings and watch videos of how they actually deal with you.

“And you will be able to hear and see for yourself how quickly they turn on you if you change your mind about helping them.”

The Met initially said it would not investigate but on Tuesday said “inquires continue to identify those responsible and whether any offences have been committed”.

Detective Chief Superintendent Stuart Cundy, of Trident, said: “Disappointingly, we are aware of a small amount of irresponsible leafleting in Southwark.

“Trident receives an incredible amount of vital community support across London. Engaging with us is not snitching but about protecting your community.

“Information from communities is vital to solving murder investigations and we will continue to successfully protect our vulnerable witnesses.”

The Streatham Guardian received no response when we tried to contact the website – which on Tuesday had been hacked and led visitors to a memorial website.

Jennifer Blake, 43, an ex-gang member and founder of Safe and Sound Youth Project, mentoring and gang exit strategies, said: “I always encourage the community to help the police. The young people in my programme always talk about snitching, that you shouldn’t snitch. The police need to build up the respect with the youngsters, too, if they want the kids to talk to them.”

The “Stop Snitchin’” slogan was used in a campaign in 2004 in Baltimore, US.

A DVD featured footage of men claiming to be drug dealers making violent threats on camera towards anyone thinking of reporting what they knew about their crimes.

T-shirts with the campaign’s logo became popular as the DVD’s popularity grew across the US.

* Three teenagers have been charged with Sylvester’s murder: 18-year-old David Nyamupfukudza, of New Cross; Sodiq Adeojo, 18, of Camberwell; and a 17-year-old who cannot be named.

Anyone with information should contact Crimestoppers anonymously on 0800 555 111.