TORONTO - Some GO trains were delayed Monday after a body was found on the tracks west of Toronto's Union station.

Toronto police Staff Sgt. Susan Thorning says the cause of death has not been determined yet and police don't know how the person ended up on the tracks.

Police have not yet released the victim's age or gender, and say the matter is still under investigation.

GO Transit reported some delays earlier in the day because of what they initially said was a trespassing investigation.

They now say one of the trains was delayed "due to a police investigation as a result of a pedestrian fatality."

Full service was expected to resume shortly.