"I conveyed to Prime Minister Cameron our serious concerns regarding allegations about unethical means used in securing 2010 contract for AgustaWestland copters," Singh told reporters after meeting with Britain Prime Minister David Cameron.
"We have sought full assistance from UK PM Cameron and he has assured me of the cooperation of his government in the investigations," he said.
A team of Central Bureau of Investigation (CBI) and defence ministry officials left for Italy Monday to get more information on the alleged kickbacks in the $750 million (Rs.3,600 crore) chopper deal.
The defence ministry had last week initiated action for cancellation of the chopper contract.
It also issued a formal show-cause notice to AgustaWestland to explain within a week why the contract should not be cancelled.