BARRIE, ONT. -- Ontario's police watchdog is investigating the death of a man in Adjala-Tosorontio shortly after an OPP officer pulled him over.

The Special Investigations Unit says the officer was driving along County Road 50 near County Road 1 just after midnight when a speeding pickup truck whizzed by.

The SIU says the officer made a u-turn to follow the truck. Provincial police say their officer pulled the driver over on the 20th Sideroad, but he took off, and the officer stayed behind.

The SIU says the officer later found the pickup truck in a ditch, west of Concession Road 5. The 49-year-old driver was pronounced dead at the scene.