A CRITICAL incident investigation has been launched after a man fell 35 floors to his death in the CBD last night.

Police negotiators were called to a unit block in Park St about 4pm yesterday after reports a man was sitting on a 41st storey window ledge threatening self harm.

media_camera Police at the scene in Park St. Picture: Bill Hearne

After several hours of negotiation, the man fell to his death about 10.20pm, falling on the roof of a car park.

A critical incident team from an independent local area command have been brought in to investigate.

media_camera Police at the scene in Park St. Picture: Bill Hearne

Police have asked for witnesses to come forward.

Anyone who can assist police should contact Crime Stoppers on 1800 333 000.

If you or anyone you know needs help, phone Lifeline on 13 11 14.