General Motors has forced out several executives and managers, including the head of its global engine operations, as the company?s recall of vehicles in India raises questions about improper emissions tests.

GM said it had dismissed the employees for violating unspecified company policies. One of the executives was Sam Winegarden, a vice-president in charge of engine programmes, who retired this week after 44 years with GM, the nation?s largest automaker. The management shake-up came after the Indian government began an investigation into the recall this week of 1,14,000 Chevrolet Tavera utility vehicles sold by GM in India. Indian news reports said the government was investigating whether GM had improperly manipulated the weight and engine performance in the Tavera during emissions testing and certification. A GM spokesman, Greg Martin, declined to say whether the employees had been forced to leave because of the government investigation.

?GM?s investigation into our recall of the Chevrolet Tavera, which is built and sold exclusively in India, identified violations of company policy,? GM said in a statement. ?GM subsequently dismissed several employees.? One person briefed on the dismissals, who spoke on the condition of anonymity, said at least 10 employees, mostly in India, were involved. The highest-ranking employee was Winegarden, who is based in the US and is the top engineer for the company?s engine operations worldwide. The company, which said it was voluntarily recalling the vehicles, acknowledged that the Indian government was aware of ?an emissions issue? with the Tavera, one of GM?s mainstream models in the country.

?GM India informed Indian government authorities of an emissions issue involving the Tavera BS3 meeting certain specifications on July 19,? the company said. The company stopped production of the Tavera in India this month.