BRUSSELS (AP) — European Union authorities say that German automakers BMW, Daimler and Volkswagen colluded to limit the development of emissions-cleaning technology in cars.

The EU antitrust regulator said Friday that after an in-depth investigation, it found the companies broke EU laws from 2006 to 2014 by illegally agreeing among themselves to limit the roll-out of the technology, which helps clean the exhaust emissions from both gasoline and diesel passenger cars.

The alleged actions would have limited Europeans' options for less polluting cars, but not their price. The probe is separate from other legal procedures against carmakers for allegedly breaching environmental laws.

Emissions have become a big topic for carmakers as authorities try to meet climate change goals and after Volkswagen admitted in 2015 that it cheated on car emissions tests.