Several key figures in Hewlett-Packard Co.'s possibly illegal investigation of media leaks were asked Friday to testify before a congressional panel.

A shareholder lawsuit also was filed Friday in a state court, alleging "substantial expense and damage" to the company from the investigators' use of a controversial ruse known as pretexting.

The U.S. House Energy and Commerce Committee requested that HP Chairwoman Patricia Dunn and General Counsel Ann Baskins appear at a Sept. 28 hearing of its Oversight and Investigations Subcommittee, HP spokesman Mike Moeller said, declining to say whether either would testify.

"HP is fully cooperating with all ongoing investigations and inquiries, including the one being conducted by the House subcommittee," Moeller said.

Attorney Larry Sonsini, who served as an outside legal adviser to HP during its investigation, was also asked to appear, as was Ronald DeLia, who runs a Boston-area private investigation firm that was hired by HP to conduct the probe.

The request was made as part of the panel's ongoing investigation into pretexting — the practice of impersonating people in order to access their personal information.

Dunn has acknowledged that she authorized the probe in which private investigators hired by HP used Social Security numbers and other personal information to pose as company directors, employees and journalists in order to access logs of their home and cellular phone calls.

As HP's staff attorney, Baskins allegedly oversaw the leaks investigation and declared it to be legal.

In Santa Clara County Superior Court, shareholder Juliet Worsham filed a lawsuit seeking to have Dunn, Baskins, HP CEO Mark Hurd and other company insiders found to have breached their fiduciary duties and abused their power. It asks for the defendants to reimburse Hewlett-Packard for any financial damage suffered by shareholders as a result of the pretexting scandal.

HP's stock, which has been all but immune to the boardroom scandal, rose 23 cents to $36.48 in early afternoon trading Friday on the New York Stock Exchange.