NEW DELHI (Reuters) - India has found cars of Volkswagen's VOWG_p.DE local unit in violation of nitrogen oxide emissions norms, a senior government official said on Wednesday, adding to a widening global scandal at Europe's biggest carmaker.

The Volkswagen logo is pictured at a dealership in Mumbai, India, September 22, 2015. REUTERS/Shailesh Andrade

The government has found significantly higher variation in some of Volkswagen’s and sister brand Audi’s diesel cars and has issued it a notice seeking an explanation, Ambuj Sharma, additional secretary in the ministry of heavy industries said.

Volkswagen has been asked to respond to the notice in 30 days, Sharma told Reuters.

The company could be fined or asked to recall cars in India if found guilty of violating the emission norms. The government could also initiate criminal action if it’s proved Volkswagen used defeat device to cheat tests for emissions, he said.

The finding comes two months after Volkswagen admitted cheating U.S. diesel emissions tests and that up to around 11 million vehicles worldwide could contain illegal software - the biggest business crisis in its 78-year history.

Volkswagen’s India unit said in a statement it had received a notice from Automotive Research Association of India (ARAI), the country’s testing agency that has been investigating whether its cars have flouted emission norms in the domestic market.

Volkswagen India would submit its response to the government by Nov. 30, said the statement.

Testing agency ARAI has found the diesel models of Volkswagen’s Jetta and Vento sedans, Polo hatchback and Audi’s A4 sedan to be in violation of the local emission norms, Sharma said.

“ARAI found significant variation on higher side ... in on-road testing of Volkswagen cars,” he said. “Normally three to four times higher than the limit is acceptable. This was higher than that.”

He did not say how many vehicles in India might be affected.