Senate Republicans have concerns about something in the background of Justice Department nominee William Baer, and this week they are considering taking the unusual step of discussing them in secret.

The Senate Judiciary Committee might close its business meeting Thursday to the public as they prepare to vote on Baer’s nomination to lead the DOJ’s Antitrust Division, Sen. Chuck Grassley (R-Iowa), the committee’s ranking minority member, announced during a September 13 hearing. Baer heads Arnold & Porter’s antitrust practice in Washington.

Republican committee “members have concerns with issues that were brought forward in the standard background investigation,” a spokeswoman for Grassley, Beth Levine, said in an email seeking clarification on the reason the discussion might be closed. She said no more details could be provided on the issue regarding Baer, or why the committee would need to discuss the matter in private.

Baer received a friendly reception from members of both parties at his nomination hearing before the committee in July. He had already submitted thousands of pages of information as part of his confirmation packet—mostly news articles in which he was quoted from as far back as 1991.

Every nominee also goes through an FBI background check, which reviews the nominee’s life back to age 18 and can pick up on details of private lives not caught during the White House vetting process. Although there is no public information about what Baer’s investigation might have turned up, background checks could pick up on any number of personal or professional issues.

Baer did not return a call for comment, instead forwarding the request to the Justice Department. An agency spokeswoman said DOJ would not be commenting on the issue. White House spokesman Eric Schultz did not immediately have any information but said he is checking into the issue.

Senate rules allow for a closed session for six reasons, including issues of national security. The last of the six reasons is a catch-all: A session can be closed if it “may divulge matters required to be kept confidential under other provisions of law or Government regulations.”

A spokeswoman for Sen. Patrick Leahy (D-Vt.), the Judiciary Committee chairman, summed it up this way: “Any member, for any reason, can ask for a closed session at any time,” Jessica Brady wrote in an e-mail. She also declined to comment on the private session on Baer’s background, saying she did not have any information about it.