Daimler may have to recall 260,000 Mercedes-Benz Sprinter vans, Bild reported Sunday.

German regulators are asking questions of the automaker, alleging it may have cheated the emissions readings.

The questions are the latest in increased scrutiny of automaker's self-reported tests by prosecutors.

Visit Business Insider's homepage for more stories.

German automaker Daimler is facing questions about the possible illegal manipulation of diesel emission readings, focused on its popular Mercedes-Benz Sprinter vans.

Bild newspaper reported Sunday that Germany's KBA vehicle regulatory authority has written the company warning that 260,000 Sprinters, sold up until 2016, may be affected.

Daimler confirmed to the dpa news agency that the KBA has scheduled a hearing to address the issue, which Bild said would likely lead to a recall.

The Stuttgart-based automaker last month was fined 870 million euros ($957 million) by city prosecutors over the certification of diesel cars whose emissions didn't comply with regulatory requirements. That fine isn't likely to have an impact on the company's third-quarter earnings, Daimler said.

The fine and questions about the Sprinter vans are the latest in a years long saga between German prosecutors and automakers. Earlier this year, Volkswagen's chief executive and chairman were both charged with market manipulation relating to the automaker's allegedly rigged engines.

Read more: Here's what Volkswagen did and how the emissions scandal has hurt the company

Porsche, a subsidiary of Volkswagen, and its subsidiary Robert Bosch, settled in May with authorities in Stuttgart for 535 million euros and 90 million euros each.