India's Prime Minister took the opportunity of a meeting with David Cameron to raise his concerns about a deal between Anglo-Italian helicopter firm AgustaWestland and the Indian air force.
Authorities in India are concerned that the £480 million contract to supply the air force with military helicopters may have broken corruption and tax fraud laws.
It follows the arrest in Italy of two executives from the firm and its parent company Finmeccanica.
Mr Cameron said it was a matter for Italian investigators, since Finmeccanica is an Italian firm, but that Britain would cooperate with any requests for information.
India's Prime Minister Manmohan Singh has told David Cameron he has "very serious concerns about unethical means" used to secure a deal between Anglo-Italian helicopter firm AgustaWestland and the Indian air force.
Mr Cameron has said that the UK will respond to any requests for information, and that he is glad that Italian authorities are investigating the matter.