Emergency services were called to reports of a van on fire in Horsley Road, Northampton, at about 4am today.
A spokesman for Northamptonshire Police said: "Sadly, a body was discovered in the back of the van.
"The death is currently being treated as unexplained and an investigation is underway."
Horsely Road, just off the A508 Barrack Road, has been taped off to the public since the incident. Forensics are on the scene.
Witnesses, or anyone with information, are asked to call Northamptonshire Police on 101, quoting incident number 55 of 13/8/18.