Microsoft has been stepping up its co-operation with law enforcement communities worldwide in an effort to combat electronic crime.

The company is to begin working with officers from Europol in the next few weeks and is already training officers at Interpol in forensic computing and online tracking. Microsoft has even had staff in Nigeria trying to tackle so-called 419 scammers.

We've had a two year relationship with Nigeria," said Roger Halbheer, Microsoft's chief security advisor.

"The police have had major success in arrests in Nigeria after a crackdown. The government was concerned about people's perception of Nigeria because of the criminals and that this would affect the ability to attract foreign investment. "

After the decision to crack down was taken the remit of the Nigeria Economic and Financial Crime Commission was extended to allow the prosecution of online financial crime. Microsoft provided training and the software tools to track criminals.

But this co-operation only goes so far Halbheer said, and rumours of back doors in the company's software that could be used by government agencies to monitor computer activity were provably false.

"There an easy proof point to there being no key," Halbheer said.

"As part of our Golden security program governments get access to our source code. The Russian government certifies our code, and you can bet they'd be looking for a back door."

There is increasing focus by companies on online crime due to fears that consumers are becoming increasingly mistrustful of the internet. Yesterday Microsoft and others set up an industry body to find ways to build more secure applications.