Harley-Davidson in $15m pollution settlement with US

The company, the iconic American manufacturer of large and loud motorcycles, agreed to buy back and cease selling so-called "super tuners," which improved performance but increased hydrocarbon and nitrogen oxide emissions.

The company has produced and sold about 340,000 of the devices, which are prohibited under the US Clean Air Act, the Justice Department said.

The announcement comes as the German automaker Volkswagen faces continuing legal woes after admitting that it had installed emissions cheating devices on 11 million diesel-powered automobiles worldwide.

Last year, the company sold about 265,000 motorcycles worldwide and 168,000 in the US.

Assistant Attorney General John Cruden, head of the Justice Department's Environment and Natural Resources Division, said in a statement that other manufacturers should consider themselves warned.

“Anyone else who manufactures, sells or installs these types of illegal products should take heed of Harley-Davidson’s corrective actions and immediately stop violating the law," Cruden said.

The settlement involves both the Justice Department and the US Environmental Protection Agency.

In a statement, Harley said it had not admitted liability and took issue with the government's legal positions.

"This settlement is not an admission of liability but instead represents a good faith compromise with the EPA on areas of law we interpret differently, particularly EPA's assertion that it is illegal for anyone to modify a certified vehicle even if it will be used solely for off-road/closed-course competition," Ed Moreland, head of government affairs, said in the statement.