Investigators from the Independent Office of Police Conduct, who are looking into the crash on Toller Lane in which four young men died, are appealing for ghoulish footage of the crash to be taken down from the internet - and sent to them.

The harrowing CCTV footage, which the Telegraph & Argus had already taken the decision not to use, emerged on social media overnight.

It shows the BMW carrying the four men driving up Toller Lane on the wrong side of the road at well over the 30mph speed limit before clipping a lamppost and crashing into the tree.

IOPC regional director Miranda Biddle said: "Footage of the incident, and the aftermath, from what appears to be private CCTV has been shared in the media and on social media. I would ask that this be removed to avoid any further distress to the men's families and those involved and instead is shared with our investigators, using the witness appeal phone line or email, so it can be examined as part of our investigation."

Footage can be sent by email to tollerlanebradford@policeconduct.gov.uk or people with footage to share can telephone 0800 0969079. Investigators also want to hear from any witnesses.

The appeal comes as investigators confirmed the dead men's identities as Murtza Chaudhry, aged 21, Arbaaz Hussain also aged 21, Zeeshan Khalid, aged 20 and Tayyab Siddique, aged 22.

They also confirmed that an unmarked police car had been following the BMW for a minute when it crashed, having spotted it traveling at excessive speed. There is no indication from the evidence that there had been any contact between the two vehicles, they added.

A funeral will take place today for all four men.