USA: Volkswagen’s top US executive has apologised as the emissions-rigging scandal engulfing the world’s largest carmaker deepened and members of Congress said the company violated the public’s trust.

“On behalf of our company, my colleagues in Germany and myself, I would like to offer a sincere apology for Volkswagen’s use of a software program that served to defeat the regular emissions testing regime,” Volkswagen of America chief executive Michael Horn told a House subcommittee.

Calling the company’s admission “deeply troubling”, Mr Horn said: “We have broken the trust of our customers, dealerships and employees, as well as the public and regulators.”

The German carmaker admitted last month that it installed on-board computer software designed to cheat on government emissions tests in nearly 500,000 of its four-cylinder “clean diesel” cars starting with the 2009 model year.

Fred Upton, chairman of the House Energy and Commerce Committee, said Volkswagen “has long enjoyed an almost cultish following dating back to the Beetle.

But through the years something apparently became rotten in Wolfsburg”.

Mr Horn, a 51-year-old German and veteran VW manager who took the reins of the brand’s American subsidiary last year, told Congress that VW plans to withdraw applications seeking US emissions certifications for its 2016 model Jettas, Golfs, Passats and Beetles with diesel engines. It was not immediately clear when VW would refile its application.