On Wednesday Ed Markey, a leader on the US House telecommunications and internet subcommittee, identified Paula Dunn and HP's ethics lawyer, Kevin Hunsaker, as being named in criminal indictments filed by California's attorney-general, Bill Lockyer.

Dunn and Hunsaker resigned from HP last month amid a growing controversy about unethical and potentially illegal tactics used to expose a board member that had been leaking company secrets to news reporters.

They resigned after it was revealed that investigators hired by HP had impersonated reporters, employees and board members to find out who was leaking inside information to the press.

Dunn was among HP executives grilled by Markey and other members of the US congress at a subcommittee hearing in Washington DC last week. Dunn repeatedly denied approving any wrongdoing.

'Pretexting'

The day-long hearing ended with HP’s chief executive, Mark Hurd, taking responsibility, apologising and vowing to back legislation to protect people from the spying tactics that were used to expose the HP director believed to have loose lips.

Hewlett-Packard confirmed on Wednesday that criminal charges had been filed against some of its executives but in a release "regarding California attorney general indictments", the company did not say who was charged and said it was continuing to cooperate with the investigation.

Private investigators obtained the telephone records of nine journalists, two HP workers, and seven current or former board members, along with their families, in a trick of impersonation referred to as "pretexting".

Markey urged Congress to pass pending legislation to increase penalties for pretexting.

Tight-lipped

"We need to pursue a new direction in this country that ensures consumers will no longer be vulnerable to intrusions into their families' privacy, either by their employer, by the government, or by criminals seeking to turn information into money," Markey said.

Hunsaker was one of 10 former HP executives and outside private detectives that declined to testify before the subcommittee.

In her statement to the House panel, Dunn contended that she had been assured by company lawyers and security veterans that all the tactics were "above board".

The House committee's senior Democrat, John Dingell, invoked the Watergate scandal in describing the subterfuge at HP as "a plumbing operation that would make Richard Nixon blush".