The congressional panel investigating Hewlett-Packard Co.’s boardroom spying probe has demanded that CEO Mark Hurd explain $1.37 million worth of options he exercised just before the scandal became public, two congressmen said Wednesday.

Hurd’s cashout on Aug. 25 — just before HP disclosed the spying tactics in a regulatory filing on Sept. 6 — did not appear to be part of a prescheduled program, the panel’s ranking members, John Dingell, D-Mich, and Bart Stupak, D-Mich., said in a letter to Hurd on Tuesday.