FRANKFURT, Germany (AP) — German prosecutors and police have searched offices at the Munich headquarters of automaker BMW in connection with an investigation into suspected manipulation of diesel vehicle emissions.

Munich prosecutors said the search Tuesday came after BMW employees admitted to Germany’s motor vehicle authority on Feb. 22 that two models — the 750xd and the M550xd — had been equipped with impermissible defeat devices that turned off emission controls under certain circumstances.

The company has said that the 11,400 vehicles in question mistakenly received software intended for other vehicles during a post-sale update, worsening emissions performance. The company says it recalled and fixed the vehicles and is cooperating with the probe.

BMW’s competitor, Volkswagen, has admitted using illegal software that turned off emissions controls in some 11 million vehicles.