A dying man was allegedly handcuffed and held down after being hit by police car, witnesses said.
Arthur Hoelscher-Ermert died from serious injuries sustained after being hit by the unmarked police car on the A259 in Peacehaven.
According to footage obtained by The Times, the 27-year-old can be heard groaning while officers restrain him face down after the collision on Saturday.
Another clip shows officers attempt CPR while witnesses can be heard shouting, "you've killed him".
A friend said he believed the police were pursuing Mr Holscher-Ermert after suspecting he had been driving without insurance.
However Mr Holscher-Ermert was hit while on foot, with a friend, named only as Matt, saying: "“Their blue lights came on and the BMW swerved over the road and hit this bloke.”

"He was rolling around on the floor in pain and in shock. There was a pool of blood around him and they were still trying to
cuff him."
Yesterday loved ones paid tribute to, with his brother Karl Holscher-Ermert saying "rest easy up there". "RIP RIP RIP my baby brother," it reads.
"Right, I don’t really have the words but need to get this out there. I have the worst news to tell everyone. Last night at roughly mid night by brother Arthur Hoelscher-Ermert was run over and killed by police on south coast road Peacehaven!
"If you have any information or evidence of you would be so kind to forward it on to me so we can figure out what has happened as Sussex Police still have made no contact with us regarding the incident! Rest easy up there my boy look after mum make sure you give her a big squeeze from me."
An array of floral tributes have been places at the A259 junction with Bramber Avenue. One tribute says Arthur Hoelscher-Ermert is "loved and missed", while another described him as a "hero".
The coastal road remained closed until about 1pm yesterday while emergency services investigated the incident, reports Sussex Live.
As the incident involved a police vehicle the matter has been referred to the Independent Office for Police Conduct (IOPC) who will carry out an independent investigation.
Officers are urging anyone with information or dashcam footage of the incident to email collision.appeal@sussex.police.uk quoting Operation Ambleside.
Chief Superintendent Jo Banks said: “This is a tragic incident and we are fully supporting the IOPC investigation. We want to thank drivers and residents for their patience while the A259 South Coast Road was closed.”