BILLINGS, Mont. (AP) – Civil rights attorneys and lawyers for the judiciary are due in federal court Tuesday for arguments over whether hundreds of racist and inappropriate emails from Montana’s former Chief U.S. District Judge should be preserved as potential evidence in future lawsuits.

Attorneys for the judiciary are seeking to dismiss the case. They said in court filings that the emails from Judge Richard Cebull are confidential and can’t be released under federal law.

But the civil rights attorneys who filed a court petition to preserve the emails contend they could prove bias in cases that came before Cebull during his 15-year career on the federal bench, including five years as chief judge for the Montana district.

Cebull resigned last year, after an investigation into a racist email he sent involving President Barack Obama that was first reported by The Great Falls Tribune newspaper.

A judicial committee determined he sent hundreds more inappropriate emails to personal and professional contacts that showed disdain for blacks, Indians, Hispanics, women, certain religious faiths and liberal political leaders. Those have not been released.

The committee that investigated Cebull’s emails found no evidence of any bias when it analyzed his cases.

Plaintiffs’ attorney Larry Organ said the issue needs to be looked at more closely.

‘‘They’re suggesting he’s a racist who didn’t practice racism in his judicial decision-making,’’ said Organ who heads the California Civil Rights Law Group. ‘‘That is something that probably needs to be explored more thoroughly in a case than left to a cursory review.’’

Organ said a separate lawsuit is planned to challenge the court’s denial last year of a request for the emails to be made public. The lawsuit will be filed on behalf of John Adams, who broke the news on the Obama email while he was a reporter at the Tribune and is now working as a freelancer, Organ said.

If that lawsuit advances, Organ said it could make the petition to preserve the emails moot because judicial officials would be obligated to retain them as evidence.

Cebull did not immediately return a telephone message seeking comment.

Under the court’s policy, his emails will be maintained for at least five years and then may be destroyed, Assistant U.S. Attorney Neill Tseng said in court documents filed last week. That period ends Jan. 18, 2019, five years after complaints over the emails were resolved by the Judicial Council of the 9th U.S. Circuit Court of Appeals.

The issue of whether the emails will be preserved for potential release so they can be used in other litigation is before U.S. District Judge Yvonne Gonzalez Rogers in Oakland, California.

Rogers already dismissed the petition once, saying in October that the plaintiff’s case was ‘‘hypothetical’’ because they did not specify any of Cebull’s cases that they hoped to challenge. However, she let them refile the petition.

Civil rights attorney Organ and his clients – two American Indians and two advocacy groups – have since said they want the emails as potential evidence to exonerate a former Crow Indian Tribe chairman of a bribery conviction.

Cebull sentenced former tribal chairman Clifford Birdinground to three years prison in 2003. Birdinground later sought to retract his plea and go to trial. Cebull rejected the request, a decision upheld on appeal.

The plaintiffs also point to a lawsuit handled by Cebull in which American Indians sought satellite polling places on several Indian reservations. Cebull’s dismissal of the request was later overturned by the Ninth U.S. Circuit Court of Appeals.