MISSISSAUGA, Ont. - The province's civilian police watchdog has cleared Peel regional police after a man died in custody near Pearson International Airport.

The Special Investigations Unit says police responded to a 911 call July 24 after 53-year-old Keith Prescod allegedly struggled with a GO Transit bus driver for control of the vehicle on Dixon Road.

Police restrained Prescod after he had left the bus and struggled with an airport employee.

He lost consciousness and was pronounced dead at Etobicoke General Hospital.

SIU director Ian Scott says that after an autopsy it appears Prescod's death was the result of a pre-existing medical condition exacerbated by the ingestion of cocaine and physical exertion.

Scott says the legal cause and manner of death will be determined by an inquest.