Duke told to keep quiet after Wikileaks disclosure

Prince Andrew came under attack after a leaked document showed he condemned anti-corruption investigations as "idiotic" in his role as UK trade ambassador.

US ambassador Tatiana Gfoeller described the duke boasting "cockily" about British influence during an expletive-laden discussion with business leaders in Kyrgyzstan in 2008.

Her report of the meeting came in a confidential diplomatic cable and is among more than 250,000 secret documents obtained by whistle-blowing website WikiLeaks.

Business Secretary Vince Cable stressed that anti-corruption policy had nothing to do with the duke and it would be "helpful" if he did not comment on Government matters.

"He is not a Government appointee. He voluntarily goes around the world trying to help British companies promote exports and jobs in Britain," said Mr Cable.

"I would just make it absolutely clear that we regard bribery overseas as illegal and unacceptable. That is not a matter for Prince Andrew, that's a matter for the Government."

However, he praised Prince Andrew for his role as trade envoy.

The duke's comments came at a two-hour brunch for British and Canadian business chiefs in 2008 and were summarised by Ms Gfoeller for State Department officials in Washington.

She claimed the duke attacked the Serious Fraud Office investigation – later closed – into alleged kickbacks relating to a giant arms deal BAE secured with Saudi Arabia.

"He railed at British anti-corruption investigators, who had the 'idiocy' of almost scuttling the Al-Yamama deal with Saudi Arabia," she wrote.

He criticised journalists who "poke their noses everywhere" and in "an astonishing display of candour", alleged that nothing got done in Kyrgyzstan unless the son of the then president got a cut, she said.

Buckingham Palace and Downing Street said they would not comment on leaked documents, as campaigners called for Prince Andrew to step down from his role with UK Trade and Investment (UKTI).

Further disclosures from the leaked US embassy cables revealed that Gordon Brown appealed to the US to allow computer hacker Gary McKinnon to serve any prison sentence in Britain.

He had suggested McKinnon, facing up to 60 years in an American prison, could plead guilty in return for not being extradited to the US. However, the then prime minister's plea fell on deaf ears in Washington.

According to The Guardian – which had advance access to the leaked documents – Mr Brown made his unsuccessful intervention in August 2009.

Mr McKinnon's mother, Janis Sharp, said she was "very surprised and very pleased" to learn of the negotiations.

But she said she was also surprised at the unwillingness of the Americans to deal.

"I think they want to make an example of him for computer crime," she said. "America does not like to lose. America likes to win.

"I think they don't see it as showing compassion and being fair. I think they see it as almost like a game – 'We win at all costs, you do as we say at all costs'."