One man has been pronounced dead following a rear-end collision on Highway 401.

It happened in the eastbound express lanes of Highway 401 at Keele Street at around 11:40 a.m.

Ontario Provincial Police said one passenger vehicle collided with the back of another.

Paramedics found a 45-year-old man in the rear vehicle unresponsive at the scene. He was rushed to hospital, where he was pronounced dead.

Police are currently in the process of notifying his family.

It was not immediately clear if the man died as a result of the crash. The damage to his vehicle was relatively minor and his injuries did not immediately appear to be consistent with a fatality, police said.

The coroner is assisting in the investigation.

A stretch of the highway was closed for the investigation, but has since reopened.