India's federal investigating agency has started an inquiry into Oxfam India after the government alleged the charity had violated the country's foreign funding regulations.

Thousands of civil society groups in India have had their licences to receive overseas donations cancelled since 2014 after Prime Minister Narendra Modi's government tightened surveillance on non-profit groups regulated under the Foreign Contribution Regulation Act (FCRA).

New Delhi did not renew Oxfam India's FCRA registration when it lapsed at the end of 2021 and Oxfam India's office was searched by the country's tax officials last September.

Oxfam India did not immediately respond to a request for comment on the inquiry but said earlier this month that it was "fully compliant" with the country's laws and has filed all its statutory compliances, including FCRA returns, in a timely manner.

"Oxfam India has been cooperating with all government agencies since its FCRA registration wasn't renewed in December 2021," it said on April 6.

Ordering a probe into the organisation this month, India's home ministry alleged that Oxfam India planned to evade FCRA by routing funds through other avenues.

"Email communication... shows that Oxfam India has been planning to pressurize the Indian government for renewal of FCRA through foreign governments and foreign institutions," the ministry said in its complaint to the Central Bureau of Investigation (CBI).

"Oxfam India has the reach and influence to request multilateral foreign organisations to intervene on its behalf with the Central government. This exposed Oxfam India as a probable instrument of foreign policy of foreign organisations/entities which have funded Oxfam India liberally over the years."

The CBI started the investigation this week based on the home ministry's complaint, according to an agency report, a copy of which was seen by Reuters. (Writing by Sudipto Ganguly; editing by Christina Fincher)