June 15 (Reuters) - Audi ⁠have blamed airborne gravel for Formula One ⁠driver Nico Hulkenberg's Barcelona-Catalunya Grand Prix retirement.

The ‌German veteran coasted into the pit lane and retired from Sunday's race when his car suddenly lost power.

The team ​later revealed it had nothing ⁠to do with reliability, ⁠with Hulkenberg saying stones thrown up by Liam Lawson's ⁠Racing ‌Bulls car had hit an emergency electrical cutoff switch on the Audi ⁠behind.

"Liam ran slightly wide ahead of me ​and put ‌a wheel into the gravel at Turn 12, ⁠which ​kicked up a lot of stones. Some of them hit our car and appear to have triggered ⁠the emergency safety switch, causing ​a complete shutdown of the system," explained Hulkenberg.

"Everything switched off instantly and that was the end of ⁠our race."

Hulkenberg had started in the top 10 for the first time this season and had been hopeful of converting that into points. Lawson ​ultimately ended up eighth.

Racing ⁠director Allan McNish confirmed the safety fire switch had ​taken a hit, triggering an ‌automatic function designed to ​shut the car down in an emergency.

(Reporting by Alan Baldwin; Editing by Toby Chopra)