Sunil Mittal (pictured), the chairman of Bharti Airtel, India’s largest mobile operator, has been ordered to appear in a court case about alleged corruption in the allocation of bandwidth dating back to 2002.

The court has also ordered two other telecoms executives to appear alongside Mittal in court next month. They are Ravi Ruia, the co-founder of the Essar Group, and Asim Ghosh, who was formerly in charge of Vodafone India.

The country’s Central Bureau of Investigaton (CBI) filed charges in December against the companies concerned in the case but did not single out individuals.

But now the court has ordered the three executives to appear on 11 April.

The case concerns a period in 2002 when Bharti Airtel and predecessor companies to Vodafone (such as Hutchison-Essar) were allocated radio spectrum.

In a statement, Bharti Airtel said: “We will fight this charge sheet”, describing it as “an attempt to tarnish its reputation”, speaking on behalf of both the company itself and the chairman.

The Essar group, speaking on behalf of itself and Ruia, said the order was “shocking and surprising” and said it was only a minority shareholder in Hutchison when the alleged offences occurred. It said Hutchison-Essar was “effectively in the hands of directors and employees nominated by the Hutchison group” at the time.