According to WikiLeaks, he said Hindu groups were more dangerous than LeT.
Congress General Secretary Rahul Gandhi had told US Ambassador Timothy Roemer that growth of "radicalised Hindu groups" which create religious tensions in India could pose a bigger threat to the country than activities of groups like Lashkar-e-Taiba (LeT).
According to a secret US diplomatic cable from New Delhi released by WikiLeaks, the Congress leader shared his views with Roemer on a range of political topics, social challenges, and electoral issues for the Congress party in the next five years.
The cable contained details of Rahul's conversation with the envoy at a luncheon hosted by Prime Minister Manmohan Singh at his residence in July 2009 in honour of visiting US Secretary of State Hillary Clinton.
"Responding to the ambassador's query about Lashkar-e-Taiba's activities in the region and immediate threat to India, Rahul said there was evidence of some support for the group among certain elements in India's indigenous Muslim community," the cable notes.
"However, Rahul warned, the bigger threat may be the growth of radicalised Hindu groups, which create religious tensions and political confrontations with the Muslim community," it said.
The cable dated August 3, 2009 which described Roemer's luncheon encounter with Rahul on July 20, 2009, noted that the Congress general secretary was referring to the tensions created by some of the more polarising figures in the BJP such as Gujarat Chief Minister Narendra Modi.
"The risk of a 'home-grown' extremist front, reacting to terror attacks coming from Pakistan or from Islamist groups in India, was a growing concern and one that demanded constant attention," it said.
The cable signed off by Roemer says that Gandhi, who was seated next to the ambassador, was forthright in describing the challenges faced by the Congress party and the UPA government in the months ahead.
The United States, which has accused WikiLeaks, of stealing its secret cables, has refused to either deny or confirm the authenticity of these cables.
"Over the past four years, he was an elusive contact, but he could be interested in reaching out to the United States, given a thoughtful, politically sensitive and strategic approach on our part," it said.
Roemer spoke about the need to reach out to the young leaders of the country.
"We will seek other opportunities to engage with him and with other promising young members of the new generation of parliamentarians," he said.
"Gandhi mentioned that in the recent election 60 members of the new Parliament were 45 or younger.
"In a system long viewed as relatively static, the influx of new faces and the rising profile of young leaders like Rahul Gandhi provides us an opening to expand the constituency in support of the strategic partnership with a long term horizon," Roemer said.
According to the cable, Rahul stressed that his focus in the upcoming months would be on state assembly elections in Maharashtra and party building efforts at the local level.
"He was busy trying to recruit more appealing candidates to run for Member of Legislative Assembly (MLA) positions nationwide," he said.
"Gandhi's focus was on finding younger party members who would not carry some of the baggage of older Congress candidates.
"He aimed at rebuilding party structures in small towns and rural areas to attract voters and believed the main opposition Bharatiya Janata Party (BJP) was vulnerable there.
The cable noted that Rahul did not seem to be as focused on electoral efforts in bigger cities, such as Delhi and Mumbai.
"Noting that the Congress Party victory in this past spring's parliamentary elections had put the United Progressive Alliance (UPA) government in a comfortable position, Gandhi still expressed concerns about the numerous challenges regarding the UPA's ability to implement its programmes in Parliament," the cable said.