The body was burned as well and only the post-mortem examination of remains taken from the Rover 416 revealed that the victim had been stabbed.

A farmer made the discovery at 0830 BST on Saturday at Millfield Lane, Caddington, near Dunstable.

Officers are linking the discovery with a burglary at the nearby Wyevale Garden Centre in which fireworks worth at least £2,000 were stolen over the weekend.

Eyewitnesses sought

Four large metal containers carrying fireworks worth were stolen from the compound.

Two of these were silver with lids on top - the others were green cabinets with doors which could be locked and one would be about five feet high, the other six feet high.

Detective Superintendent Nicky Dahl said he was anxious to hear from anyone who could help with the inquiry.

In particular he is looking for anyone who had seen any of the four containers dumped anywhere or being transported.

An incident room has been set up at Dunstable police station on 015 8247 1212 or people can call CrimeStoppers anonymously on 0800 555111.