After years of complaints from Republicans and allies of the president, Attorney General William Barr revealed that the FBI is being investigated over FISA surveillance on the Trump campaign in 2016.

"The Office of the Inspector General has a pending investigation of the FISA process in the Russian investigation, and I expect that that will be complete in probably in May or June, I am told," said Barr during congressional testimony Tuesday.

The president alleged that he had been "wire tapped" by the former Obama administration, which later admitted that some members of the campaign had been surveilled during an investigation into claims of Russian interference in the 2016 election.

"So hopefully we'll have some answers from Inspector General Horowitz on the issue of the FISA warrants," added Barr.

He also said that he was personally looking into the controversial acts of the FBI.

"More generally," Barr said, "I am reviewing the conduct of the investigation and trying to get my arms around of all the aspects of the counter-intelligence investigation that was conducted during the summer of 2016."

Senator Lindsey Graham (R-S.C.) has also said that Barr is interested in investigating how the FBI came to the conclusions they made about former Democratic presidential candidate Hillary Clinton's transgressions over her private email server.

And here's the point," said Graham. "How could she win if the Department of Justice indicted her? I think that's what drove the decision not to indict."

"They wanted her to win," he concluded.

Here's part of Barr's testimony: