Detroit (AFP) - Two US owners of General Motors diesel pickup models sued the giant automaker on Thursday, claiming it had used emissions-cheating devices similar to those in Volkswagen's global "dieselgate" scandal.

The company quickly denied the allegations.

The lawsuit, filed in a Detroit federal court, came the same week that US authorities brought legal action against Fiat Chrysler, accusing the company of likewise configuring diesel-powered vehicles to deceive emissions tests, an allegation the company denies.

In court papers, Andrei Fenner of California, the owner of a 2011 GMC Sierra pickup, and Joshua Herman of Louisiana, who bought a diesel Chevrolet Silverado in 2016, said testing showed that GM was no different than Fiat and Volkswagen in hiding harmful nitrogen oxide emissions.

The two pickup models "emit far more pollution on the road than in the emission certification testing environment," according to their complaint.

The trucks allegedly employ "at least three different 'defeat devices' to turn down the emissions controls when the vehicle senses that it is not in the certification test cycle," it added.

The lawsuit, which claims to represent the interests of other owners, also accuses the German auto supplier Bosch of involvement in the alleged scheme. Bosch participated in the development of defeat devices for Volkswagen and agreed to compensate US consumers earlier this year.

In a statement on its website, GM said there was no truth to the allegations.

"These claims are baseless and we will vigorously defend ourselves," the statement said, adding that both pickup models complied with all emissions regulations.