BARRIE -- Investigators are appealing to the public for information after a man was hit by his own truck and seriously injured in Bradford last week.

South Simcoe Police say the victim's vehicle was at a stop sign heading north on Drury Street at Thomas Street when, for some reason, the 67-year-old man got out of the truck.

The details aren't clear, but police say another person who was inside the vehicle drove over the man and then took off.

"I saw the old man hanging, and then I saw him drop," said Andrea Pinheiro, who was out that evening with her children. She describes hearing an engine revving. "It was just the revving that made me look back."

Police say the victim was dragged about 20 metres.

He was taken to hospital with critical injuries and later sent to a Toronto trauma centre where he remains.

"We are still missing some information here, exactly how the victim ended up outside the vehicle and who got into the driver's seat and drove away, causing the injuries," said Sgt. Brad Reynolds.

Investigators said the truck was found abandoned a short time later at Frederick and Toronto streets.

The truck is a 2015 Dodge Ram with the license plate AK42726.

Anyone with information is encouraged to contact South Simcoe Police or Crime Stoppers to leave an anonymous tip.