The government on Tuesday asked five telecom operators, including state-run BSNL, to give their accounting details for three years from 2006-07 to the Comptroller and Auditor General of India.

The Comptroller and Auditor General of India (CAG), the apex audit body, had earlier decided to audit accounts of five telcos -- Bharti Airtel, Reliance, Tata, Vodafone and BSNL.

According to official sources, the Department of Telecom in a letter to all these five companies asked to furnish certain documents to CAG from 2006-07 to 2008-09.

Sources said even though for 2007 and 2008 fiscal, special audit have already taken place recently of the four private telecom companies, CAG is keen on redoing the audit for these years again and also as it is not satisfied with the special audit result.

So far auditors, who ironically are also appointed by CAG, only have submitted reports on Bharti Airtel and Reliance Communications, while for Vodafone Essar and Tata Teleservcies it is still going on.

DoT has asked the companies to give service-wise revenues, other sources of income, supplementary and support income, total cost of operation and operational expenses.

Sources said telecom regulator TRAI has already appointed a nodal officer to facilitate this audit exercise.