FBI director Christopher Wray said he would not describe FBI investigations as "spying" on Tuesday, responding to a question about Attorney General Bill Barr's assertion that law enforcement officials "spied" on the 2016 Trump campaign.

Sen. Jeanne Shaheen: "When FBI agents conduct investigations against alleged mobsters, suspected terrorists, other criminals, do you believe that they're engaging in spying, when they're following FBI investigative policies and procedures?"

Wray: "Well that's not the term I would use."

Shaheen: "So I would say that's a no to that question?"

Wray: "Well, I mean, lots of people have different colloquial phrases. I believe the FBI is engaged in investigative activity, and part of investigative activity includes surveillance activity of differing shapes and sizes. And to me the key question is making sure that it's done by the book, consistent with our lawful authorities."

Why it matters: Barr's claim that "spying" by law enforcement officials on the 2016 Trump campaign "did occur" during a Senate testimony last month caused significant backlash from Democrats who believed he was purposely using a term with explosive connotations. Barr added that he did not mean "improper surveillance" necessarily occurred, but that he is looking into it.

During his testimony this month, Barr doubled down, telling Sen. Sheldon Whitehouse: "I'm not going to back off the word spying except I will say I'm not suggesting any pejorative and I use it frequently, as do media."

When Sen. Whitehouse responded that the term is "not commonly used by the department," Barr replied: "Well, it's commonly used by me."

Wray said he didn't think he "personally" had any evidence that illegal surveillance of any campaign occurred. The inspector general is currently conducting an investigation into the origins of the Russia probe.