Quoting from a letter which the television channel said National Security Adviser M K Narayanan wrote to the central and state governments in November 2005, Times Now said two Lashkar activists had joined the IAF.
Narayanan's letter was based on an assessment made by the National Security Council Secretariat.
The national security adviser refused to comment if the letter was authentic.
Speaking to the channel from Chennai, rediff.com columnist and former Research and Analysis Wing official B Raman said he thought the language in the letter was authentic and Narayanan's signature appeared to be real.
The IAF told the channel that it checks and rechecks the antecedents of its personnel, making it difficult for a Lashkar operative to infiltrate its ranks.
The Times Now television channel is jointly owned by Bennett Coleman & Co, publishers of The Times of India newspaper, and Reuters News Service.
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