The DoT has also asked the company, which is a 100 per cent subsidiary of British Telecom, to immediately stop all telecom services in India.
According to DoT officials, the company had violated the Indian Telegraph Act by providing VPN services without approval from the Government of India.
This had resulted in loss to the exchequer, as the company had not paid the requisite licence fee, the department said. While the company was selling telecom services in India, customers were being billed from its Singapore office, it added.
VPN services are used to link large corporate houses, industries, banks, retail chains and offices with branches spread across different cities.
A senior BT (India) executive refuted the charges and said the company had not violated the provisions of the Telegraph Act as it did not offer telecom services in India.
"We have already filed an appropriate response to the DoT's notice. The Indian subsidiary only provides global network support and services to British Telecom and is not involved in providing telecom services in India," the executive added.
In August 2005, the DoT had issued similar show cause notices to overseas telecom carriers AT&T, MCI Worldcom and Equant for allegedly providing such services without approval.
BT (India) Pvt Ltd had applied for Internet service provider, Internet telephony and Internet protocol-virtual private network licences in March 2005, but is yet to receive the government's approval.
"The government has not responded to our application for licences to begin operations in India," a company executive added.