Google Inc. filed a motion under seal Tuesday to address matters that previously caused a judge to abruptly adjourn an administrative hearing between the company and the U.S. Department of Labor over its alleged failure to turn over data on its hiring practices.

Google filed its sealed motion April 18 at the instruction of Administrative Law Judge Steven Berlin, who is presiding over the hearing in the Office of Administrative Law Judges in San Francisco.

Attorneys said that it was an unusual move for the venue, and it could have been done to protect confidential or privileged information or data belonging to Google.

“It’s rare within the administrative law ‘world,’ for an [administrative law judge] to ask for any additional briefing,” said John Barber, co-chair of the labor and employment practice at Lewis Brisbois Bisgaard & Smith’s Los Angeles office. “It’s exceptionally rare for an [administrative law judge] to ask for sealed briefing. I’ve never heard of such a request,” Barber said.

Tammy Daub, of counsel at Paul Hastings and former senior attorney for the Office of the Solicitor—which provides legal services to agencies within the Labor Department, the Office of Federal Contract Compliance Programs included—said in her personal experience with the Office of the Solicitor, she did not recall a time when an administrative law judge asked for motions to be made under seal. But, she said, it can still happen.

“The judge may limit the introduction of material into the record or issue orders to protect information against undue disclosure of sensitive material,” Daub said. “Here, the issues are around compensation data and contact information.”

On April 7, Google defended itself before the Office of Administrative Law Judges against claims that it did not comply with a request for employee compensation data as part of an audit by the Office of Federal Contract Compliance Programs.

At that hearing, Google’s attorneys argued that much of the data the OFCCP asked for—employee names, phone numbers, email addresses and physical addresses—infringed on the privacy of the company’s workforce. The attorneys also argued that much of the other data the OFCCP sought, including job history, salary history and bonus history, had no relevance on how employee compensation is calculated at Google.

Lawyers for the OFCCP, including trial attorney Marc Pilotin and counsel Ian Eliasoph, argued that the OFCCP asked for employee contact information during its audits so that federal government investigators can confidentially interview employees to see if their statements line up with findings from employee compensation data.

At the hearing, the OFCCP regional director Janette Wipper also made the explosive claim on the witness stand that, based on a partial analysis of initial data Google sent, the federal agency found “systemic compensation disparities against women pretty much across the entire workforce.” Google strongly denied the claim.

Though the administrative hearing in San Francisco was scheduled to finish that day, at roughly 3 p.m. Pacific Standard Time, Jackson Lewis partner Lisa Sween, representing Google, told the judge she and her counsel needed to discuss a “significant matter.”

Sween explained she was concerned about proprietary information being unintentionally released to the public. Sween did not return a phone call seeking comment.

Berlin then removed members of the public and media from the hearing, and later instructed Google’s counsel that it had until April 12 to file a motion under seal to address the issues just discussed. Berlin later extended that deadline and also allowed the OFCCP until April 25 to respond with a motion under seal of its own.

The issue of gender pay equity has long plagued companies.

George Chaffey, Littler Mendelson OFCCP practice group co-chair, said it is “not very common” for the department to have a complaint against a company escalate to being heard by an administrative law judge. He, too, said he had never heard of an administrative law judge asking for a motion to be filed under seal in a hearing. He said that, because he is not familiar with the complaint against Google, he could not assume why Berlin requested for motions to be made under seal.