Italian police appear no nearer to releasing Roberto Preatoni, founder of vulnerability auction start-up Wabisabilabi, four days after he was taken into custody in Milan.

The company Preatoni founded in stealth mode last year released a terse and brief statement yesterday, but appear as in the dark as everyone else as to the precise nature of the charges, and any timescale for his release.

“Roberto Preatoni Strategic Director of WabiSabiLabi has been arrested and remains in custody in Milan. WabiSabiLabi can not comment on the open investigation or the statements being made in the press,” it said.

“From newspaper reports we presume the arrest relates to events in 2003/04 when his former company was hired by Telecom Italia's Security division to safeguard Telecom Italia’s interests and are unrelated to WabiSabiLabi in any way,” it continued, betraying a degree of bewilderment on the chain of events or their likely outcome.

“Mr Peatoni's unfortunate arrest has not affected the day-to-day operations of the WabiSabiLabi. Roberto Preatoni is well known for his terrific contribution to information security and civil liberty and we are confident that his innocence will be established if a case ever comes to court,” it concluded.

Preatoni appears to have become enmeshed in a high-profile and long-running investigation regarding alleged spying on a number of companies and individuals by a penetration-testing team working at Telecom Italia.

His absence from Wabisabilabi is bound to have an effect on his company, but only if it becomes protracted. The Switzerland-based company remains in the capable hands of its CEO, Herman Zampariolo, but Preatoni’s technical influence and expertise will be missed.

In a separate development, Microsoft has defended its decision to invite the Preatoni to speak at its Blue Hat security event in September, on which Preatoni blogged enthusiastically.

"If you bring this guy in and he talks to your development force, he says I am buying vulnerabilities against your products and they have value. Make your products better because I am your enemy," he said. "So the fact that he got arrested, I’m not happy about it because I thought he was a good guy. But what do I know?," said Microsoft’s George Stathakopoulos.

The controversial business model of Wabisabilabi, the world’s first auction site for security holes, still elicited some hostility, Stathakopoulos admitted.

"Some people say god I hate this guy; people say 'why did you bring him over here?'" But when people internalise it and step back and they think about it a little they think, 'I've got a lot of work to do [on vulnerabilities],'" he said.

Additional reporting by Robert McMillan, IDG News Service.