Canterbury Police say information from the public could prove key to finding out how a gang-member was shot in the head.

The 40-year-old man remains in Christchurch Hospital after he was dropped off outside the doors early Sunday morning.

Detective Senior Sergeant Jason Stewart says they recovered a green/blue Subaru which dropped him off and forensic examinations are continuing.

He says sightings of the car may help police find the two men who were in it.

"Central to our inquiry. We'd like to hear from anyone who may have information on it's movements."

The victim's family have asked for his current condition to remain private.