The Bosch logo is seen in Reutlingen, Germany, June 16, 2017. REUTERS/Michaela Rehle

FRANKFURT (Reuters) - Prosecutors in the German city of Stuttgart are looking into a possible fine for auto supplier Robert Bosch for providing Volkswagen with engine management software that the carmaker used to cheat vehicle emissions tests in 2015.

Volkswagen has paid out more than 27 billion euros ($31 billion) in penalties for using illegal software to disguise excessive levels of pollution from its diesel cars, triggering a global regulatory clampdown that has now reached Bosch.

“It is correct that the Public Prosecutor’s Office of Stuttgart has opened monetary fine proceedings against Robert Bosch GmbH,” a spokesman for the company said in a statement on Friday.

“The proceedings relate to the investigations against employees of Robert Bosch GmbH in connection with the use of allegedly manipulated software in control units of diesel vehicles,” Bosch added.

German prosecutors last year fined Volkswagen 1 billion euros and its sister brand Audi 800 million euros for management oversight lapses which allowed polluting cars to hit the road.

German weekly magazine Der Spiegel reported on Friday that Volkswagen was reviewing whether to seek damages of up to 1 billion euros from Bosch. Volkswagen declined to comment on the report.

Bosch said: “Relationships with customers are kept confidential. The automaker-supplier relationship between Bosch and Volkswagen goes back over decades. We cannot imagine such an action against Bosch.”

($1 = 0.8828 euros)