FBI Director James Comey said Wednesday that Hillary Clinton's decision to bring nine lawyers to her interview with investigators in early July was "unusual."

"It's unusual to have that large a number, but it's not unprecedented," Comey said during a hearing before the House Judiciary Committee.

Two of Clinton's personal attorneys, Cheryl Mills and Heather Samuelson, were granted immunity in the case and were later permitted to accompany Clinton to her voluntary interview with FBI agents.

"Ms. Mills, in particular, was a member of Secretary Clinton's legal team, and so Secretary Clinton decides which of her lawyers come to voluntary interviews with the FBI," Comey said, adding that his agents have no power to prevent targets or subjects from bringing the representation of their choice to interviews.

The FBI director said Mills' attorney asked the Justice Department for immunity before the former Clinton aide would hand over her laptop. Agents later discovered classified emails on Mills' hard drive.

Comey noted "there was a lot of immunity" granted throughout the investigation, which he described as a "complex" and "white collar" criminal probe.