News of the stricter approach is prompting multinational companies, risk consultants and fraud compliance lawyers to make sure they or their clients stay within the law.

In April, the newly created FCPA unit of the US Securities and Exchange Commission in San Francisco announced that technology companies' activities in Asia would be its special focus.

'The fact that we have a significant presence of companies in Silicon Valley who do business internationally, specifically in Asia, makes us well suited for addressing these kinds of issues,' Tracy Davis, assistant regional director in charge of the new unit, told the Daily Journal, a Californian-based legal affairs publication.

'That's one of the reasons why San Francisco is a particularly good location for an FCPA unit.'

The tougher line comes at a time when US prosecutors have won lucrative settlements from some of the world's most well-known companies, in cases involving business dealings in China.

'China is by far the single most involved country in FCPA matters,' said Joseph Warin, a partner at Gibson, Dunn and Crutcher in Washington.

Since 2002, activities on the mainland have been involved in 27 actions taken under the FCPA, ensnaring firms including General Electric, Lucent Technologies, AGA Medical, Siemens, ITT Corporation and Daimler. 'The regulators are following multinationals and the places where they are going - which is China in particular,' Warin said. 'They have had a track record of prominent enforcement matters coming out of China.'

In 2007, Lucent agreed to pay an out-of-court settlement of US$2.5 million to the US government after prosecutors accused the company of paying for 315 trips to America for Chinese government officials to go on 'factory inspections' or 'training'. These visits mostly comprised sightseeing in major US cities, the Grand Canyon and Disneyland.

The following year, Siemens settled on a compensation of US$1.6 billion to the US and German governments after it was charged with giving bribes in China, among other countries, to secure projects ranging from construction of metro trains and high-voltage transmission lines to the sale of medical equipment.

This year, Daimler agreed to pay US$185 million after being accused of making tens of millions of US dollars in improper payments to foreign officials. Its Chinese subsidiary allegedly gave more than US$5.6 million to local government officials in the form of commissions, gifts and travel.

Warin said his firm was now involved in an investigation on the mainland that was being handled by the Californian FCPA unit.

'I think you'll see China, India, Indonesia, Taiwan and Southeast Asia as targets of scrutiny by the West Coast office.'

The crackdown on foreign graft began during the US administration of George W. Bush, said Nathan Hochman of the law firm Bingham McCutchen, and continued under US President Barack Obama's watch.

At a meeting of the Organisation for Economic Co-operation and Development last month, top US prosecutor Eric Holder said: 'As attorney general, I have made combating corruption one of the highest priorities of the Department of Justice.'

The US has company in the global crackdown - Britain recently passed the 2010 Bribery Act, which, when implemented in full force, will be even stricter than the FCPA.

The British legislation no longer limits the definition of bribery to foreign officials. It creates a separate offence for a company that fails to prevent a bribe being paid on its behalf.

Beijing is also enforcing the mainland's anti-corruption laws more aggressively. In recent years it has conducted high-profile prosecutions of senior government officials, who were jailed or even executed.

For foreigners trying to cut deals in Asian countries, embracing the local business culture - which relies heavily on building relationships, or guanxi, through the exchange of favours and gifts - can lead companies to quickly run afoul of the US act.

Hochman pointed to 'a historical practice in Asian countries in acquiring payments by government officials for government contracts'.

The mainland has a reputation for graft not only among US prosecutors. China was ranked 79th out of 180 countries last year on Transparency International's Corruption Perceptions Index, which scores nations based on surveys of people working in the country or abroad. China had the fourth-lowest ranking of G20 nations, with only Argentina, Indonesia and Russia scoring lower.

Moreover, the mainland presented unique challenges because the government was directly involved in so many segments of the commercial cycle, said Richard Tollan, a Hong Kong-based partner at law firm Mayer Brown JSM who specialises in fraud and insolvency cases.

'The government may be involved in business directly or through state-owned enterprises; the government may be your banker, your supplier, your manufacturer or your customer,' Tollan said.

The State-owned Assets Supervision and Administration Commission controlled 152 companies earning 1 trillion yuan in profits, said Barry Naughton, a professor at the University of California, San Diego.

More and more, companies operating on the mainland were taking a pre-emptive approach against corruption, by hiring senior compliance officers who could made decisions on the ground, training employees and doing better due diligence with potential business partners, said Ho, who handles mainland projects.

'We are seeing more prevention and detection efforts on the parts of the companies. In the past, we see reaction after an event. But at that point, you are trying to put toothpaste back in the tube,' she said. 'Now, we are being more engaged by companies earlier on.'

Tightening the noose

US officials are checking firms that bribe their way into foreign deals

Since 2002, the number of actions taken under the Foreign Corrupt Practices Act that involved China is: 27