When asked why he had sent the letter, Roy said: “I have the country’s security interests in mind. Mobile phones and Internet are being increasingly used by terrorists. So when an Indian telecom company enters into a deal with a foreign player, the Government should keep the security aspect in mind.”

So why didn’t he write the letter when Reliance Communications was in talks with MTN?

“I came to know of the deal only now. I am not saying don’t give the deal to Bharti, I am only highlighting the security aspect.”

In his letter, Roy claims that MTN’s presence in India will be a “threat to national security” as many of “the key national leaders, Ministers, MPs, Government officers, including those holding sensitive positions, use Airtel.”

Roy has a curious track record of sending letters to various Ministers on corporate matters. Once, he wanted the security approval given to Jet Airways chief Naresh Goyal revisited; he favoured Reliance Infocomm’s proposal to pay lower royalty to Qualcomm and even sought a probe into the assets of a former Union Finance Secretary.

Recently, he wrote a letter to the PM seeking the resignation of Mendu Rammohan Rao, a former independent director on the board of Satyam Computers, from various government committees. Rao was a member of government panels to select the chairman and members of SEBI, the chairman of the Telecom Regulatory Authority of India and the deputy governor of the Reserve Bank of India.