Williams has revealed that the accident that saw Rubens Barrichello crash out of the Monaco Grand Prix was caused by a loose manhole cover.

The Brazilian went into the barriers at Beau Rivage after apparently suffering an issue with the left rear of the car, with Williams initially revealing earlier this week that his car had suffered a problem with its suspension.

Following further investigation however, the team has now confirmed that the problem was in fact caused by Barrichello's car being hit by a loose drain cover, which damaged the left rear wheel and caused it to fail.

The matter has been reported to the FIA.

"Following an investigation, AT&T Williams confirmed today that the cause of Rubens Barrichello's crash at the Monaco Grand Prix on Sunday 16 May 2010, was a loose manhole cover at Turn 2," a short missive from the team read. "As Rubens' car drove over the manhole cover, it was spun up and hit the rear left wheel, causing failure. The car was badly damaged in the ensuing crash which ended Rubens' race. This incident has been reported to the FIA."