India's parliamentary Defense standing committee is to question the heads of India's three military branches.

The committee's concerns arise from comments by outgoing Indian army chief Gen V. K. Singh, who had red-flagged India's defense preparedness in a confidential letter addressed to the Prime Minister Mamohan Singh's office. That letter was subsequently leaked to the media.

Sources familiar with the parliamentary request, speaking on condition of anonymity, remarked that the legislative committee's decision to summon the heads of India's army, air force and navy for a presentation on April 20.

The session is seen as part of an ongoing effort by parliamentarians to evaluate and understand issues related to defense preparedness as the committee evaluates the upcoming Defense Ministry proposed budget for the 2012-13 fiscal year.

Analysts note that the parliamentary summons is unusual as, in the recent past, the three service chiefs have appeared before the standing committee only once, the Press Trust of India reported.

Seeking to maximize the input of testimony while minimizing the disruption of the work of the armed forces heads, the source said committee members would allow the date for their appearance to be adjusted to ensure that all the three military chiefs are available on the same day.

The committee was particularly concerned to uncover details about the movement of two army units, one in Agra in Uttar Pradesh and another in Hissar in Haryana, toward New Delhi on Jan. 16-17, reported on the media as a "routine drill."

At a preliminary committee meeting Indian Defense Secretary Shashi Kant Sharma, reading from a prepared statement, said no permission was required from the Ministry of Defense for such an exercise.

He sought to downplay the report as containing "wrong inferences, conclusions and conjecture" and that the deployment was in line with army standard operating procedures and that media reports were "misleading."

Following Sharma's testimony, committee members Abbas Naqvi, Manish Tewari, Naresh Gujral and Uday Singh stated that the matter should be treated as closed.

This was the second meeting of the parliamentary committee on recent controversies surrounding the army, including recent bribery allegations.

Sharma's testimony didn't specifically address a number of substantive issues raised by committee members, with Sharma remaining silent when asked by AIMIM MP Asaduddin Owaisi whether he had told the director general of Military Operations to recall the troops back, a question Owaisi first posed at the committee's last meeting.

Several committee members said they were also skeptical about Sharma's explanation about Minister of State for Defense Minister M.M. Pallam Raju's comments that "probably someone down the (government) line may have read too much" into the troops' movements toward the capital three months ago.