WASHINGTON — Attorney General William Barr said Monday the Justice Department is taking information that President Trump’s personal lawyer Rudy Giuliani is gathering in Ukraine about the president’s Democratic rival Joe Biden and his son.

Attorney General William Barr appears at a news conference, at the Justice Department in Washington on Monday. Jacquelyn Martin/Associated Press

But Barr cautioned that federal officials have “to be very careful” with information coming from Ukraine. The attorney general’s comments at an unrelated news conference in Washington come a day after Sen. Lindsey Graham said Barr told him the department had “created a process that Rudy could give information and they would see if it’s verified.”

“The DOJ has the obligation to have an open door to anybody who wishes to provide us information that they think is relevant,” Barr said. “But as I did say to Senator Graham, we have to be very careful with respect to any information coming from the Ukraine. There are a lot of agendas in the Ukraine, a lot of cross currents. And we can’t take anything we received from Ukraine at face value.”

The prospect that Giuliani is providing potentially damaging information about one of the president’s political rivals to the Justice Department while Giuliani is under federal investigation is likely to deepen criticism from Democrats that Barr acts more like the president’s personal lawyer than the attorney general.

Federal prosecutors in New York are investigating Giuliani’s business dealings, including whether he failed to register as a foreign agent, according to people familiar with the matter. They were not authorized to discuss the investigation publicly and spoke on the condition of anonymity.

Giuliani also was a main character in Trump’s impeachment, which centered on Trump’s dealings with Ukraine’s president and whether he abused his office by seeking an investigation into the Bidens.

In this handout photo provided by Adriii Derkach’s press office, Rudy Giuliani, left an attorney for President Trump, left, meets with Ukrainian lawmaker Adriii Derkach in Kyiv, Ukraine, in December. Adriii Derkach’s press office via AP

Giuliani, a former New York City mayor who often appears in rambling television interviews as a vocal defender of the president, has been pushing unsubstantiated corruption allegations against Biden. Speaking to Fox News on Sunday, Giuliani said he has a document that relates to Biden’s son, Hunter, along with a memo allegedly from a Democratic Party official documenting communications with a reporter.

The Democratic-controlled House voted to impeach Trump, alleging abuse of power and obstruction of Congress for pressing Ukraine to investigate the Bidens, while delaying delivery of nearly $400 million in congressionally-approved security assistance for the Eastern European nation. Hunter Biden served on the board of a Ukrainian gas company while his father managed the U.S. government’s Ukraine portfolio under President Barack Obama.

Trump was acquitted earlier this month by the Republican-led Senate.

Barr said the Justice Department had established a process to collect the information and that it would be carefully scrutinized but left a news conference without taking any additional questions about the process.

“We had established an intake process in the field so that any information coming in about Ukraine could be carefully scrutinized by the department and its intelligence community partners, so that we could assess its provenance and its credibility,” Barr said. “And that is true for all information that comes to the department relating to the Ukraine, including anything Mr. Giuliani might provide.”

FBI Deputy Director David Bowdich said the agency was “taking information as we would in any case” and that federal agents would “will evaluate it appropriately.”

Bowdich would not answer when asked whether Joe or Hunter Biden were under investigation by the FBI.

Hours after Barr’s comments, the House Judiciary Committee sent a letter to the Justice Department demanding that the attorney general answer a series of questions about Giuliani’s information.

Committee Chairman Jerrold Nadler sent 11 questions about the process, who would be involved and whether it would be shared with the White House.

“Any official relationship between Mr. Giuliani and the Department raises serious questions about conflicts of interest – both for the Department, generally, and for you, specifically,” Nadler wrote to Barr.

Nadler’s letter notes that one of Giuliani’s associates, Lev Parnas, has said Barr was briefed on efforts to pressure the Ukraine government to investigate Democrats. Parnas is charged with illegally funneling foreign money into U.S. political campaigns.

The Justice Department said last year that Parnas’ claims were “100 percent false.”