Almost half of British businesses have little or no understanding of one of the risks they face when doing business in the US despite the publicity surrounding the extradition to the US of the "NatWest Three" and their subsequent guilty pleas.

That is according to a new survey by KPMG Forensic, which revealed that 46 per cent of legal department heads at FTSE350 companies which conduct business in the US either wrongly believe they are immune from US prosecutors or simply do not know whether they might fall under their jurisdiction.

KMPG surveyed general counsels and company secretaries at FTSE350 companies on their awareness of the US Foreign and Corrupt Practices Act (FCPA), legislation that allows US authorities to prosecute foreign companies and individuals with a “US footprint” for corrupt practices involving public officials.

Under the Act, British companies leave a US footprint if they do business in the country or if they use American financial institutions as advisers.

Although the FCPA is a separate piece of legislation from that used to prosecute the "NatWest Three", it represents another example of the reach of American authorities.

The US Department of Justice (DOJ) and the Securities and Exchange Commission (SEC) have both been active in prosecuting companies under the FCPA and have the power to request the extradition of British citizens.

In July, the US law firm Shearman and Sterling said the DOJ was investigating a record 55 public companies for alleged overseas corruption. These include BAE Systems, the British defence contractor, which is under investigation for alleged bribes paid to Saudi Arabian official.

Criminal prosecutions by the DOJ carry fines of up to $2 million (£970,000) per violation per company and $100,000 (£48,000) per offence for individuals.

Officers, directors, employees or agents of companies under investigation can also face up to five years in an American jail.

The survey also found that of the British companies that acknowledged their obligations under the FCPA, more than half — 56 per cent — did not have, or did not know whether they had, an FCPA compliance program.

Jennifer Hammond, a director at KPMG Forensic, said: “The lack of awareness by companies of the scope of US anti-corruption laws is especially concerning. The US regulators take an uncompromising approach to this issue, and have carried out an increasing number of investigations since 2001."

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