The struggling Spyker Formula One team said they had delayed the introduction of their revised car until next month after it failed a rear impact crash test.

The team said at the Turkish Grand Prix, where the B specification car was to have made its race debut tomorrow, that the car would be launched at the Italian Grand Prix instead.

"It's obviously very disappointing to delay the launch," said technical director Mike Gascoyne in a statement.

"Unfortunately last week we had an unexpected failure of the rear crash test, possibly due to problems with a batch of material used.

"All the structures we had to test were from this batch and the modifications we tried to make were not sufficient," added the Briton.

"We are confident that we understand the problem however and should be able to pass with no problems next week."