Attorney General William Barr said Tuesday he is "reviewing the conduct" of the FBI's initial investigation into the Trump campaign in the summer of 2016.

During a House Appropriations panel hearing, Barr also said he is open to reviewing criminal referrals from House Intelligence Committee ranking member Devin Nunes, R-Calif., targeting eight people tied to the origins of the Trump-Russia investigation.

"I am reviewing the conduct of the investigation and trying to get my arms around all the aspects of the counterintelligence investigation that was conducted in the summer of 2016," Barr testified.

The FBI's original Russia investigation, which began in July 2016, was later wrapped into special counsel Robert Mueller's inquiry looking into Russian meddling in the 2016 election and possible collusion between President Trump's campaign and the Kremlin.

Republicans, including Nunes and Rep. Mark Meadows, have long been engaged in their own investigations into alleged misconduct and bias within the upper echelons of the Department of Justice and FBI, including the anti-Trump text messages of former FBI officials Peter Strzok and Lisa Page, which they are concerned will reveal a scheme to undermine Trump.

Nunes has not disclosed any names of people ensnared in his referrals, but he did break down three categories in which they fall on Sunday, including conspiracy to lie to Congress and the Foreign Intelligence Surveillance Court. Nunes also suggested his effort could drastically expand to encompass dozens of people.

Barr said Tuesday he has not yet seen these referrals, but when he does, he added, "Obviously, if there is a predicate for investigation, it will be conducted.”

Barr's examination of the initial Russia investigation could intersect with an investigation by U.S. Attorney John Huber, who was appointed by former Attorney General Jeff Sessions in March 2018 to look into GOP claims of FBI misconduct.

Senate side, Judiciary Chairman Lindsey Graham, R-S.C., says there will be continued investigations into the origins of Mueller’s investigation and potential bias in the Justice Department and FBI, including a look at FISA warrants.

Barr provided a four-page summary of Mueller's roughly 400-page report to Congress last month which said the special counsel did not establish the Trump campaign colluded with Russia. The summary also said Mueller did not find Trump committed obstruction of justice, but Mueller also did not exonerate the president. However, Barr said he concluded there was insufficient evidence to establish a crime.

Barr testified Tuesday that he will be ready to release a redacted version of Mueller's final report to the public within a week.