The results of Bridgestone's investigation into the cause of Dani Pedrosa's damaged front tyre at the Japanese Grand Prix, round two of the 2009 MotoGP World Championship, have been announced.

Pedrosa finished in third position at Motegi, from a lowly eleventh on the grid, but returned to the pit lane with chunks missing from his front tyre (pictured), prompting Bridgestone to apologise for the isolated case and launch an investigation.

Following Sunday's French Grand Prix at Le Mans, Bridgestone revealed the cause of the chunking.

"After a detailed inspection, we found a small foreign object that had become embedded within the tread of the front slick," said Tohru Ubukata, Bridgestone Motorsport's manager of Motorcycle Race Tyre Development.

"This was the origin of a weak point in the tread of the tyre which, during the course of the race, worked its way to the surface, causing a crack to form in the rubber."

Bridgestone did not state when, or how, they believe the foreign object became 'embedded'.

If the object only became embedded during the race then it would point to debris from an earlier accident. It if was already present before the race then a manufacturing or fitting fault is likely.

After finishing third at Motegi, Pedrosa finished second at Jerez and then third again last weekend at Le Mans, placing him fourth in the championship standings, just nine points from leader Jorge Lorenzo.