The government-appointed special auditors, looking into books of telecom firm Bharti Airtel for alleged under-payment of licence fee, is understood to have submitted its report to the Department of Telecom.

Sources in the know confirmed that the auditors, who probed if the company had shown more revenue under heads that attract lower licence fee, has been submitted but declined to divulge details about the findings.

A similar audit has been ordered on Vodafone-Essar, Tata Teleservices, Idea Cellular and RCom. While the report on RCom was submitted late last year, the others are likely to come out by March 15.

According to senior officials in the DoT, a special audit for all the integrated telecom companies will be undertaken, as suggested by telecom regulator TRAI, once in 3-5 years.

DoT's action comes after TRAI found a jump in revenue from long distance segment, in case of Bharti Airtel, which attracts only six per cent licence fee as against up to 10 per cent for other mobile services.

When contacted, Bharti spokesperson declined to comment. Under the country's telecom policy, all telecom firms have to pay the government 6 per cent to 10 per cent of their annual revenues as licence fee and another 2 per cent to 6 per cent of their annual revenues as spectrum charge.