Police are trying to determine what caused a Pembroke-area man to lose control of his all terrain vehicle - killing him instantly.

Lorne Trautrim, 43, was riding his ATV Sunday afternoon on Station Hill Road in Laurentian Valley Township when his vehicle left the bush road and overturned. He was pronounced dead at the scene.

Police say Trautrim was riding with another man who lost control of his bike as well. He suffered not life-threatening injuries.

Although police are still piecing together their investigation, they say the ATV did not collide with the bike.

A post mortem to determine Trautrim's cause of death is scheduled for Tuesday at the Ottawa General Hospital.