German automaker Volkswagen is facing a new round of criticism after the company was found to have funded tests of its diesel engine emissions on captive monkeys as part of an attempt to brand its vehicles as clean, safe and healthy.

As first uncovered in an episode of the documentary Dirty Money that began airing on Netflix on Friday and subsequently reported on by the New York Times, VW, Daimler and BMW funded an institute designed to come up with research to support the notion that diesel engines are cleaner and safer than other fuel alternatives.

The now defunct European Research Group on Environment and Health in the Transport Sector, known as EUGT — whose budget consisted entirely of funds from the three automakers — didn't do research of its own, but rather commissioned academics to produce reports that might paint diesel in a favourable light, the Times report says.

In one such experiment conducted at a lab in New Mexico in 2014, researchers put 10 macaque monkeys in sealed rooms and pumped in exhaust fumes from a Volkswagen Beetle for four hours. Another group of monkeys was exposed to fumes from an older Ford pickup, for comparison. The monkeys were later anesthetized and examined to see what the fumes did to their bodies. Other tests involved willing human subjects who were exposed to similar conditions.

In 2015, Volkswagen had a major scandal on its hands when many of its diesel-powered cars were found to have been programmed to bypass emission controls, except during emissions tests. Now, it's under fire for reportedly funding tests that exposed captive monkeys to diesel fumes. (Mal Langsdon/Reuters)

On Monday, the German government condemned the experiments and Volkswagen tried to distance itself from them.

"In the name of the whole board I emphatically disavow such practices," VW chair Hans Dieter Poetsch said.

He said the tests must be "investigated completely and without reservation."

Steffen Seibert, a spokesman for German Chancellor Angela Merkel, said the "tests on monkeys or even humans can in no way be ethically justified.

"They raise many critical questions for those behind these tests, and these questions must urgently be answered."

'Unjustified'

Daimler AG said it was "appalled by the nature and extent of the studies." Though the company said it didn't have any influence on the studies' design, it has launched a "comprehensive investigation into the matter."

BMW said that it "did not participate in the mentioned study" on animals "and distances itself from this study."

The test was conducted before Volkswagen was exposed in 2015 for cheating on emissions tests to make its cars appear to spew out far fewer pollutants than they did in real-world conditions.

And while the monkey test results were never published, the Times story has sparked criticism from experts who question what exactly the company hoped to accomplish.

"It's torturous and unjustified," bioethics professor Kerry Bowman of the University of Toronto said in an interview, "and what they were trying to prove is not completely clear."

While once common, Bowman says testing on animals is much less so these days because the public's tolerance for it has decreased. Much of it occurs in the medical and pharmaceutical fields, where researchers have to get approval from an ethics board and abide by rigorous parameters for safety and humane treatment — all after they've proven the benefits of the experiment could potentially outweigh the costs.

"I do not believe that this could ever meet the criteria," Bowman said. "And it comes on the tail of the emissions scandal, which was ethically problematic in the first place."

Bowman said the experiment as described seems more like a bumbled attempt at marketing than legitimate scientific research.

Marketing professor Alan Middleton at York University's Schulich School of Business agrees with that assessment, saying the scheme was likely one of the automaker's attempts to promote diesel as a cleaner fuel alternative. But he says with news of animal testing coming on the heels of the company's original emissions scandal, "what people are going to take from this is that they are doing something else bad again."

Middleton says Volkswagen's rivals will be eager to capitalize on the company's latest troubles, seeing as it was once renowned for its innovation and engineering acumen.

"People will be circling them looking for blood, waiting for bad stuff to happen, so they better not have any more scandals up their sleeves."