A damaged seal on Michael Schumacher's fuel rig was to blame for a pitstop fire at last weekend's Austrian Formula One Grand Prix, Ferrari said on Wednesday.

The team said a small amount of fuel had remained in the breather hose of the fuel rig after it was used to supply Brazilian team mate Rubens Barrichello's car on lap 21.

The same rig was then used to refuel world champion Schumacher when he came in for his first stop two laps later.

"It appeared that a seal was damaged on the breather hose, so the fuel left inside it was able to escape, thus starting a fire, which was further exacerbated by vapour escaping from the same hose," said a Ferrari statement.

The incident, with fuel leaking on to the Ferrari's red-hot exhausts, could have cost Schumacher the race but instead the German stayed calmly in his car before roaring out of the pitlane to retake the lead.

Formula One's governing body has said it would also investigate the flare-up while Ferrari promised a step-by-step review of the problem.