A Northern Territory man may be flown to Adelaide after a party trick involving setting off firecrackers  between his buttocks went badly wrong.

The 23-year-old man was at a party in the Darwin suburb of Rapid  Creek on Saturday night when he decided to let the cracker off, NT police said.

''It appears a party was in full progress when a young male  decided to place a firework between the cheeks of his bottom and  light it,'' said Senior Sergeant Garry Smith.

''What must of seemed to be a great idea at the time has  backfired, resulting in the male receiving quite severe and very  painful burns to his cheeks, back and private bits,'' Senior Sgt Smith  said.

Alcohol was a possible factor involved in the stunt, police  said.Paramedics were called although the man had reportedly already  taken himself to hospital by the time they arrived.

On Monday police said they believed he would be flown to a  specialist burns unit at the Royal Adelaide Hospital.

A Royal Darwin Hospital spokeswoman was unable to confirm the  man would be flown to Adelaide but said flights to the specialist unit would indicate he had was seriously injured.

The man's woes may not be over once his burns heal.

Police said anyone possessing fireworks outside of an approved period faces a $282 ($NZ 365) fine.

Fireworks in NT can only legally be set off on July 1, known as Territory Day, when the region celebrates its anniversary of being  awarded self-governance.

After that day they must be disposed of, but fireworks are often  set off for weeks afterwards as people use leftover supplies.

- AAP