The Mueller report may not show collusion between Russia and President Trump's campaign, but European anti-trust regulators say they have found collusion among German automakers to avoid cleaning up tailpipe emissions.

On Friday, anti-trust regulators for the European Union charged BMW, Daimler, and Volkswagen with colluding to block the introduction of effective diesel and gasoline emissions technology.

Two years ago, European Union officials raided the offices of all three automakers looking for evidence of such collusion after tests in the U.S. and Europe showed that diesels produced by the company (as well as, later, in Jeeps and Ram trucks produced by Fiat Chrysler), emitted as much as 40 times the allowable limits of nitrogen oxides when driven on the roads.

READ THIS: EU investigating diesel collusion among Audi, BMW, Mercedes, Porsche, VW: report

The diesel scandal showed that the cars were designed only to operate their emissions control systems to maximum effect when the cars were run in the confines of emissions tests.

In letters to the three automakers, officials alleged that the collusion took place during technical meetings of the "circle of five" German automakers, including Volkswagen divisions Porsche and Audi, between 2006 and 2014, according to a Reuters report. 

“Daimler, VW, and BMW may have broken EU competition rules. As a result, European consumers may have been denied the opportunity to buy cars with the best available technology,” said European Competition Commissioner Margrethe Vestager in a statement to the press.

CHECK OUT: German authorities uncover emissions-cheating collusion among diesel automakers

The charges are focused on the automakers' use of selective catalytic reduction systems, or urea injection, as well as "Otto" particulate filters for gas-powered cars.

In two class-action lawsuits in the U.S., involving later versions of Volkswagen's 3.0-liter diesel V-6 and 2.0-liter diesel turbo-4 engines, the cars were found to utilize too little urea "diesel exhaust fluid," to effectively clean up emissions. These are the cars that Volkswagen did not buy back, but updated the software to use greater amounts of urea.

READ MORE: Germany fines BMW over diesel emissions

Volkswagen has already paid $1.2 billion in fines in Germany over its diesel emissions shortfalls. BMW and Daimler have paid $9.5 million. All three automakers have shifted their focus from developing new diesels to spending billions of dollars to develop electric cars and build up supplies of batteries to power them.

EU regulators said the new charges are not related to emissions cheat devices. but to failing to offer the latest, most effective emissions reduction technologies to European consumers (for both gas and diesel engines.)

Volkswagen and BMW each face hefty additional fines related to the charges. BMW set aside $1.1 billion to cover possible fines, but told Reuters it will fight the charges by every legal means available. Volkswagen has not responded to the charges, saying it needed time to review them. Daimler does not expect to be fined, because it alerted authorities to the alleged collusion.