Williams: Too early to explain cause of punctures.

Williams have confirmed that they - and Michelin are to launch an investigation to discover why both Mark Webber and Nick Heidfeld twice suffered right rear tyre failures during the Turkish GP Sunday.

Speaking after the race, Williams' technical director, Sam Michael refused to speculate on what might have caused the issue, something that only afflicted them - however he added that owing to this, they had no choice but to withdraw.

"It is disappointing that we had to retire both cars from the race," confirmed Michael. "However, after the two rear tyre incidents on each car, we had no choice. It is too early to speculate what the cause is but we are looking into it now with our tyre partner, Michelin."

Michelin's director of F1 activities, Nick Shorrock was disappointed that Williams had problems.

"During the course of the race we had an incident with the right-rear tyres on both BMW WilliamsF1 Team cars and we are going to analyse fully the cause of these incidents in conjunction with the BMW WilliamsF1 Team," he added.

"We are obviously going to check with all of our other partners but to date this is a problem that we have seen only on the BMW WilliamsF1 Team cars. We are obviously very disappointed for BMW WilliamsF1 Team here at the inaugural Turkish GP."