Global companies may attempt to use bogus whistleblowers to mire their rivals in long-winded and commercially costly internal investigations into bribery overseas - and industry standards may be required to block the practice, the conference heard last week.

Stephen Yslas - assistant general counsel at US-based defence company Northrop Grumman Corporation - told the conference on anti-corruption enforcement he suspected that at least one whistleblower alleging corruption was 'floated by an agent in a rival company'.

He said: 'I felt duty-bound to investigate.

I did question the source and the credibility of the source, and that should inform the extent to which one conducts a thorough investigation.

I felt it was likely to have been planted by a competitor.'

Mr Yslas explained that companies such as Northrop conduct thorough inter-departmental inquiries in relation to such corruption allegations, and that attempts to plant bogus claims were potentially very damaging.

Mr Yslas added: 'I wonder whether or not industry standards should be introduced to prevent bogus whistleblowing from happening.'

Tim Dickinson, a partner with Washington DC-based law firm Dickinson Landmeier, told the conference that corrupt journalists could also play a pivotal role.

He said: 'There are some places in the world where rival companies can effectively buy themselves stories in the local press.

These are communicated to the local embassy and then - as a result of irresponsible reporting - an investigation is launched.'

Meanwhile Kurt Herrman, chief of compliance at Zurich-based bank ABB, told the conference that in-house counsel should consider the psychological state of whistleblowing employees alongside legal issues when dealing with corruption allegations.

He said: 'Legal issues are important but you should also be able to look after people as well.'

Jeremy Fleming