They will be questioned alongside HP chief executive Mark Hurd and former chairwoman Patricia Dunn in a US House Energy and Commerce Committee panel that is looking into the dubious practice known as pretexting, during hearings that begin today.

The third-party investigators were hired by HP and likely were part of its investigation into leaks to the media during 2005 and early 2006.

Congress defines pretexting as the use of lies and deception to gain access to information that is not publicly available and without the victim’s consent. In the case of the HP probe, the company has admitted it hired investigators who falsely assumed other people’s identities in order to open online phone accounts.

The scandal involved nine reporters, seven HP directors, two HP employees and various family members, and also implicates HP in carrying out physical surveillance and going through people’s trash.

During the past two weeks since it surfaced, the revelations from the original Silicon Valley company, which is credited for launching the industry from its humble beginnings in a storied Palo Alto garage, has shocked the broader tech community.

If Bill Hewlett and David Packard were still alive, they would be appalled. They would be embarrassed, Hurd is expected to say in his prepared testimony for the hearings, which was provided yesterday.

In addition to the five investigators, who hail from Colorado, Georgia, Florida and Texas, the congressional panel subpoenaed another private eye, Ron DeLia, operator of Boston-based Security Outsourcing Solutions Inc, earlier this week. While HP has admitted hiring DeLia’s firm to do some of its snooping, it has not yet identified the other subpoenaed firms as being part of its investigation.

Two former HP execs also were subpoenaed earlier this week, and they resigned from the company soon after.

Along with Hurd and Dunn, the congressional panel also will question several other HP officials and outside counsel. Hurd recently took over from Dunn as chair of the company’s board of directors after she resigned last Friday; two weeks after the spying scandal broke.

Dunn quit the company’s board after her announcement that she would resign as chair in January. However, in her written testimony for the congressional panel, she admits the board asked her to resign last Thursday because it had become unanimous in its view that the company could not move beyond the controversy if I remained as director.

They asked me to resign and suggested that it would be best for me if it were announced that I had come to this decision on my own, Dunn said in her testimony.

Later on, her testimony reads, The saying that ‘a reputation made over a lifetime can be ruined in minutes’ has a sickening level of resonance for me.

While Hurd has until now tried to distance himself from HP’s internal snooping, his written testimony allows for a degree of mea culpa. He admits to approving the use of sending an email to a reporter that contained false information in order to identify the source of the leaks.

What’s more, I understand there is also a written report of the investigation addressed to me and others, but unfortunately I did not read it. I could have, and I should have, reads Hurd’s prepared testimony, echoing comments he made at a press conference Friday.

The probes eventually outed HP director George Keyworth as the leaker, who has recently retired once the scandal surfaced.

Congress’ enquiry into HP’s dubious investigative methods is part of its Oversight and Investigations Subcommittee’s eight-month investigation into pretexting and data brokers.

Bryan Wagner of Littleton, Colorado; Charles Kelly of the CAS Agency in Villa Rica, Georgia; Cassandra Selvage of Eye in the Sky Investigations in Dade City, Florida; Darren Brost of Austin, Texas; and Valerie Preston of InSearchOf Inc in Cooper City, Florida.