Washington (CNN) - Former Internal Revenue Service Commissioner Douglas Shulman, who was at the helm of the IRS during most of the period agents were targeting conservative groups, will testify before the House Oversight Committee Wednesday, a House GOP aide tells CNN.
Shulman – no longer in the government – agreed to attend voluntarily.
Another official at the heart of the scandal, Lois Lerner, has told the committee through an attorney that she is currently in Montreal, and it's unclear if she can make the hearing. Lerner is the head of the IRS tax exempt division. She learned her employees were singling out conservative groups for excessive scrutiny in June of 2011, and Republican congressional investigators say she never told Congress – despite at least one face-to-face meeting.
Lerner has hired heavy hitter attorney Billy Taylor, who represented former International Monetary Fund Director Dominique Strass-Kahn in his sexual assault case.
Also testifying: Deputy Treasury Secretary Neil Wolin and the IRS inspector general.