The US government is launching a criminal investigation into VW's falsified emissions figures

The US Department of Justice has launched a criminal probe into Volkswagen's falsification of emissions data, Bloomberg news is reporting.

Last week, the Environmental Protection Agency accused the automaker of falsifying the data using secret software in nearly 500,000 cars.

According to Bloomberg's Del Quentin Wilber, two government officials close to the situation say the Justice Department is conducting a criminal investigation into the allegations.

Last week, the EPA accused VW of using the hidden software - called a "defeat device" - to dodge clean-air standard during emissions testing.

"Using a defeat device in cars to evade clean air standards is illegal and a threat to public health," assistant administrator for the Office of Enforcement and Compliance Assurance Cynthia Giles said in a statement on Friday.

"Working closely with the California Air Resources Board, EPA is committed to making sure that all automakers play by the same rules. EPA will continue to investigate these very serious matters."

The EPA alleges that VW installed software that detects when the car is undergoing emissions testing, at which point the software would turn on all of the car's emissions control systems. But the EPA claims that the software greatly reduces the cars' pollution-control systems during normal driving conditions.

"This results in cars that meet emissions standards in the laboratory or testing station, but during normal operation, emit nitrogen oxides, or NOx, at up to 40 times the standard," the EPA said in a statement.

Across the Atlantic, the German government is also taking a look at Volkswagen's emissions data. A spokesperson for the country's Motor Vehicle Agency told the Wall Street Journal that is has asked automakers to provide accurate emissions information to "determine whether similar instances of manipulation have taken place in Germany or Europe," However, there is no word of any official investigation on the part of the German government.

Over the weekend, VW CEO Martin Winterkorn issued the following statement:

The U.S. Environmental Protection Agency and the California Air Resources Board (EPA and CARB) revealed their findings that while testing diesel cars of the Volkswagen Group they have detected manipulations that violate American environmental standards.

The Board of Management at Volkswagen AG takes these findings very seriously. I personally am deeply sorry that we have broken the trust of our customers and the public. We will cooperate fully with the responsible agencies, with transparency and urgency, to clearly, openly, and completely establish all of the facts of this case. Volkswagen has ordered an external investigation of this matter.

The recall affects 482,000 diesel-powered cars sold in the US since 2008. They include:

• Volkswagen Jetta TDI: 2009-20015
• Volkswagen Beetle TDI: 2009-2015
• Audi A3 TDI: 2009-2015
• Volkswagen Golf TDI: 2009-2015
• Volkswagen Passat TDI: 2014-2015

A spokesperson for the Justice Department declined to comment on the matter.

We have reached out to Volkswagen for comment. We will update when when we hear back.