Hewlett-Packard Co.'s (HPQ) early efforts to plug a boardroom leak targeted the phone records of then-Chief Executive Carly Fiorina, according to a person familiar with one of the investigations looming over the computer and printer company.

Fiorina's quest to identify the media's sources triggered the chain of events that has ensnarled the company in criminal and congressional probes.

The Palo Alto, Calif.-based company obtained Fiorina's phone records in 2005 after she initiated HP's first attempt to identify the director leaking information to the media, according to the person who spoke on condition of anonymity because the investigation is continuing.

Fiorina declined to comment Tuesday, said Allison Sweet, a spokeswoman for the Penguin Group, which is publishing her highly anticipated book. HP spokesman Ryan Donovan also declined to comment.

HP fired Fiorina in February 2005, but the company's determination to find the source of the media leaks apparently never wavered.

Picking up where Fiorina left off, HP Chairwoman Patricia Dunn renewed the investigation into the company's board earlier this year after the publication of another story containing information she thought should have remained confidential.

HP's investigators resorted to a deceptive act known as "pretexting" to obtain the private phone records of several directors and at least 12 other people, including journalists. To pull off the ruse, HP's investigators masqueraded as the targeted individuals, using parts of their Social Security numbers to dupe telephone companies into turning over their calling records.

Dunn said she didn't know the investigators were going to such extremes. The investigation relied on at least two outside firms, Security Outsourcing Solutions Inc. of Needham, Mass. and Action Research Group of Melbourne, Fla.

California Attorney General Bill Lockyer and several federal agencies have launched inquiries to determine whether the tactics in HP's investigation broke any laws. Lockyer already has said he has enough evidence into indict individuals inside and outside the company.

A congressional panel that has scheduled a Sept. 28 hearing to examine HP's investigation wants Dunn as well as several other key figures involved in the probe to testify. The panel, the House Energy and Commerce Committee, said Tuesday that it has expanded its witness list to include Anthony Gentilucci, HP's global security manager, and Joe Depante, owner of Action Research.

Besides Dunn, other people asked to testify next week include: Ann Baskins, HP's general counsel; Larry Sonsini, HP's outside lawyer; and Ronald DeLia, who runs Security Outsourcing.

HP already has publicly apologized for his role in the imbroglio and shaken up its board.

Dunn will turn over the reins as chair to HP CEO Mark Hurd in January, although she will stay on the board. George Keyworth II, the director that HP blamed for the media leaks, resigned last week, following another board member, Tom Perkins, who resigned in protest four month months ago.