This was the shocking moment dashcam footage captured a UK van driver losing control on the M4 and crashing on the motorway with devastating results.

The footage filmed shows a white van in the slow lane of the motorway veer into middle lane traffic resulting in the filmer's car spinning out of control over all three lanes.

Some involved have speculated online that the driver of the van was asleep at the wheel but nothing has been confirmed from official sources.

The filmer explained: "I was travelling through a 50mph section of the M4 at the end of February when a van, straddling lanes 1 and 2 collided with two cars, one in the inside lane and one in the middle lane.

"After contact with the silver Mercedes, he continues to veer into the outside lane and clip the back off my car sending me spinning across all three lanes.

"The driver eventually stopped."

The footage was captured on February 28.

I was travelling through a 50mph section of the M4 at the end of February when a van, straddling lanes 1 and 2 collided with two cars, one in the inside lane and one in the middle lane. After contact with the silver Mercedes he continues to veer into the outside lane and clip the back off my car sending me spinning across all three lanes. The driver eventually stopped.