Police investigating the mysterious death of a man found in a burning car near Rotorua should learn today how he was killed.

But it may be some time before he can be identified.

A group of local cyclists called 111 to report a fire on Tumunui Rd, about 17km south of Rotorua, at 9.25am on Saturday.

Firefighters found a car ablaze with a man's body inside. It is not known where in the car the body was found.

Detective Senior Sergeant Mark Loper said the death was being treated as suspicious, however police were keeping an open mind about what happened.

The man's body was removed from the charred car yesterday. It was taken to Auckland, where a post mortem examination will be done this morning.

He said the man's identity remained a mystery, but officers were working on finding out who he was.

"Obviously it will take some time to complete identification," Mr Loper said.

The car, covered by a police tent, was in the middle of a forestry block - well away from the nearest houses in the rural area.

Police and forensic scientists were continuing an examination of the scene last night. Mr Loper said the scene would remain under guard until that examination was complete.

The gruesome death comes just three months after 28-year-old Auckland mother Ranjeeta Sharma was found burning on a rural road west of Huntly.

Mrs Sharma's husband, Diwesh Kumar Sharma, 29, has been charged with her murder. Police allege she was still alive when she was set on fire.