German prosecutors raided Bayerische Motoren Werke AG's Munich headquarters and the automaker's engine plant in Steyr, Austria, relating to alleged use of illegal emissions control software that can manipulate exhaust levels, Reuters reported.
About 100 law enforcement officials raided BMW's offices, the news agency noted. A fraud investigation against an unknown suspect was launched in February.
"There is an early suspicion that BMW has used a test bench-related defeat device," prosecutors said in a written statement.
BMW said in a statement that the prosecutors are checking "erroneously allocated" software in approximately 11,400 vehicles of the BMW 750d and BMW M550d models.