Volkswagen on Sunday apologized for financing research that used monkeys to test the health effects of diesel exhaust.

The New York Times reported recently that Volkswagen, with fellow German carmakers Daimler and BMW, paid for an experiment using monkeys in rigged studies meant to produce lower pollution levels.

“The scientific methods used to conduct the study were wrong,” Volkswagen said. “Animal testing is completely inconsistent with our corporate standards. We apologize for the inappropriate behavior that occurred and for the poor judgment of individuals who were involved.”

The apology is the latest fallout from the global emissions cheating scandal that Volkswagen started in 2015 when the company admitted it sold “clean diesel” vehicles containing software designed to cheat U.S. emissions tests.

The automaker faced federal prosecution, costing Volkswagen more than $26 billion in fines.

As part of the lab experiments, carried out in 2014, monkeys were forced to squat inside the cars and watch cartoons as they inhaled diesel exhaust for hours.

Researchers would then check the lung tissue of the monkeys to check for inflammation.

The Volkswagen Beetle used in the tests contained software causing it to produce less pollution than the car would exhaust on the road.

The organization that commissioned the study, European Research Group on Environment and Health in the Transport Sector, received all of its funding from Volkswagen, Daimler, and BMW.

Daimler said it will investigate its role in the study.

“We will clarify how the study came about and have launched an investigation,” the company said. “Daimler does neither tolerate nor support unethical treatment of animals. The animal experiments in the study are superfluous and repulsive.”

BMW said Sunday that it “does not carry out any animal experiments,” adding, “The BMW Group did not participate in the mentioned study and distances itself from this study.”