Automaker Volkswagen's head of external relations and sustainability has stepped aside from his duties after the controversy over experiments in which monkeys were exposed to diesel exhaust.

The company said in a statement Tuesday that Thomas Steg was stepping away from his duties at his own request.

The statement from the automaker said that the company was "drawing the first consequences" as it investigates the activities of EUGT, the entity backed by Volkswagen and other carmakers that commissioned the monkey experiment.

The move follows a report in The New York Times that the now-disbanded EUGT commissioned the test to show how Volkswagen's diesel technology was succeeding in controlling harmful emissions.

But the test was done with a vehicle that used illegal software to cheat on emissions tests, turning controls off when the vehicle was not being tested. That practice was exposed in 2015, toppling then-CEO Martin Winterkorn.

Volkswagen CEO Matthias Mueller said in the statement that "we are investigating in detail the work of EUGT, which was dissolved in 2017, and drawing the necessary conclusions." He said that Steg "has declared that he takes full responsibility, and I respect that."