Raising serious concerns over allegations of "unethical means" used in the Rs 3600 crore VVIP chopper deal involving Anglo-Italian firm AgustaWestland, Prime Minister Manmohan Singh today secured assurance of full assistance from his British counterpart David Cameron in the matter.

The AgustaWestland choppers, which India has ordered for use by its top leaders, are partially built in the UK. Westland used to be a UK firm and was taken over by Italian defence giant Finmeccanica.

After having wide-ranging talks which included key issues of nuclear energy cooperation, security, terrorism and trade with Cameron, Singh said he conveyed India's "serious concerns" pertaining to the chopper scam and sought his "full assistance" on the issue.

Giving details of his discussions, he said "I also conveyed to Prime Minister Cameron our very serious concerns regarding allegations about unethical means used in securing the 2010 contract for AgustaWestland helicopters.

"I told him that we have sought an explanation from the company by February 22 to examine if the contractual provisions on unethical practices and the Integrity Pact have been violated. I have sought full assistance from the UK in this case. Prime Minister Cameron has assured me of the cooperation of his Government in the investigations."

On his part, Cameron said, "In terms of AgustaWestland... we will respond to any requests for information. I am glad the Italian authorities are looking into this issue in detail as Finmeccanica is an Italian company, a parent company of AgustaWestland."

The British Prime Minister is here at a time when India is taking steps to scrap the chopper contract in the wake of allegations by Italian investigators that aerospace group Finmeccanica had broken the law by paying bribes to foreign officials to secure the deal and arrest of its chief.

India has already issued a note verbale and met with UK Foreign Office officials to get information and assistance in probing the allegations of corruption in the deal.

Noting that the UK has provided an interim response, the MEA has said they were awaiting a "full-fledged response". 

"Let me make it absolutely clear that in Britain, we have introduced an anti-bribery legislation that is probably the strongest anywhere in the world and will root out any problem of bribery or corruption whenever and wherever they appear," Cameron said.

Earlier in Mumbai, where the British Prime Minister stayed for a night before arriving here in the morning, he was quoted as saying by British media that "AgustaWestland is an excellent company, with highly skilled workers who make brilliant helicopters. Britain has ... Some of the toughest laws in the world, so people know if they do business with British companies, they have protections".

He also added that it was for the UK's Serious Fraud Office to decide whether to look into the claims.

Thanking Cameron for Britain?s support for India's full membership of the Nuclear Suppliers Group and other multilateral export control regimes, Singh said," We have also decided to commence negotiations on a bilateral Civil Nuclear Agreement."

Cameron also expressed willingness on UK's part to "rewrite" the rules on sharing technology in a bid to increase high-tech exports and said he had detailed discussions on defence and security cooperation, including in the field of cyber security.

Singh noted that he had very "candid and productive discussions" on regional and global issues and shared their perspectives on the security and political transition in Afghanistan.

"Prime Minister Cameron and I agreed that in keeping with our strategic relationship, it is important for our two sides to consult closely and remain sensitive to each other's interests," Singh said.

Noting that they had discussions at length to enhance cooperation in fighting terrorism, Cameron said both countries have been victims of terrorism and "We will work together.

"We agreed on the need for a stable and secure Pakistan which is at peace with itself and with its neighbours and which will eradicate the threat the terrorists pose both within and beyond its borders. We said that must include Pakistan bringing to justice the perpetrators of the terrible attack in Mumbai and we will work together to that end."

He said the two sides discussed the situation in Afghanistan. "Let me make it clear that Britain is not abandoning Afghanistan. We will continue to support Afghanistan even after our troops have left through the training of the Afghan armed forces and we will back that with substantial longterm economic aid."

Cameron said it was part of the international plan to prevent the war-torn country from becoming a "safe haven" for terrorists once again.