Simi Valley, Calif. ? A congressional panel wants to question key figures in the scandal surrounding Hewlett-Packard Co.’s investigation of media leaks, while a shareholder lawsuit was filed in state court accusing the company’s top brass of breaching its duties.

The House Energy and Commerce Committee sent letters Friday requesting that HP Chairwoman Patricia Dunn and general counsel Ann Baskins appear at a Sept. 28 subcommittee hearing.

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

Commerce’s Oversight and Investigations Subcommittee has been conducting an inquiry 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.