Detectives have launched a nationwide appeal for information after a man was killed leaving a festival.
Paul Wickerson, 32, was struck by a car after leaving the Brownstock festival site at Stow Maries on Saturday, August 31.
Since his death, a 32-year-old man from Sawbridgeworth has been arrested on suspicion of manslaughter.
A 48-year-old man from Ilford was also arrested and bailed until February 19.
A 29-year-old man from Shoeburyness was arrested on suspicion of manslaughter and a 36-year-old man from Southend was arrested on suspicion of perverting the course of justice.
However, officers believe that they must widen the search as the festival attracts people from across the county and the rest of the UK.
Investigations have already established that Mr Wickerson left the festival site at Woodham Road at about 10.21pm.
He died around 10.45pm when he collided with several cars at Lower Burnham Road, Cold Norton, near the junction with Fambridge Road.
Investigating officer DC Keith Sloggett, of the Kent and Essex Serious Crime Directorate, said: "We are seeking any information as to where Mr Wickerson was during his final hour. We believe that he was walking along the road wearing just a pair of shorts.”
"The investigation is also looking to gain information about how Mr Wickerson arrived at the location where he was involved in the collision which is approximately two-and-a-half miles from the festival.
"In addition to that we are also keen to hear from anyone that was ejected from the festival that weekend.”
Anyone with information should contact DC Sloggett at the Colchester MIT office on 101, call Crimestoppers on 0800 555111 or email SCDappeals@essex.pnn.police.uk.