The Department of Telecommunications has allotted a special auditor each to four telecom companies.
According to sources in the telecom ministry, Contractor, Nayak & Kishnadwala has been appointed to examine the books of Bharti Airtel, while S K Mehta & Co will check Vodafone-Essar's accounts.
Varma & Varma has been appointed as auditors for Tata Teleservices, while Chhajed & Doshi will examine the books of Idea Cellular.
The DoT is conducting a special audit on companies that have multiple licences -- mobile, international long distance, domestic long distance and internet service provider among others.