Police today hope to identify the person who died when a campervan was engulfed by flames in south Canterbury yesterday.

A passing motorist noticed the van ablaze shortly after 7am at a reserve at Hanging Rock, about 23km southwest of Geraldine.

A post-mortem examination in Christchurch this morning would help to identify the body, Timaru Detective Sergeant Dylan Murray said.

Police would also look for clues in the burnt-out Toyota Hiace, which was taken to Timaru for examination yesterday.

The van was privately owned but it was too soon to say if the owner was the person who died in the fire.

The van had been destroyed in a short space of time, Mr Murray said.

"It was extremely fierce and, like most vehicles fires, there's plenty of burnable substances inside."

Police and Fire Safety officers were working to establish the cause of the blaze.

It was too soon to say whether it was suspicious.

Police were speaking to people who had seen the van parked at the reserve.