Harvard Law School Dean Martha L. Minow has authorized an investigation into managerial practices at the Law School after a delegation of custodial workers went to her office and submitted a letter of complaint about what they called “new and discriminatory policies.”

The alleged practices, according to the letter, include unfairly firing longtime workers and requiring workers who speak Spanish to learn English.

“People have been told they are no longer allowed to be seen not working,” said Jeb Mays, an interpreter who accompanied the delegation to Minow’s office. “That they are not able to buy food from the cafe or sit down or that they are not allowed into the new building. And longtime workers have been told that they are gone for no reason.”

Workers also say that they are being discriminated against because they speak Spanish.

“A major issue is that workers have been told that they have to learn English or that they will no longer have a job,” said Wayne M. Langley, the director of higher education for SEIU Local 615, the union that represents Harvard custodial workers. “As we understand the law, if the job doesn’t require English they can’t discriminate against non-English speakers. As one worker said to me, ‘My bucket doesn’t need English.’”

The Law School said that they responded to the complaint almost immediately after it was presented by the delegation.

“After receiving the letter on Friday, the Law School referred the matter to the appropriate labor relations staff at the University for review and follow-up,” Robb London, a spokesperson for the Law School, said in a statement. “An inquiry is now underway, in accordance with the applicable University policies and procedures.”

Kevin Galvin, a spokesperson for the University, said that the nature of the complaint has made it a high priority for University labor officials.

“We take allegations of discrimination very seriously,” Galvin said in a statement. “Representatives of the Law School and the University’s Office of Labor and Employee Relations are meeting directly with union representatives and the staff members involved in order to gather information about the complaint.”

While workers were initially doubtful about whether the University would act promptly, Langley said he has so far been pleased with the Law School’s quick response.

“We’ve made clear certain issues and they’ve agreed to look into them,” Langley said. “We’re very happy with how it’s worked out.”

Langley said that workers and the Law School Labor relations staff will continue to work together in order to promote a smooth and expedient investigation.

Workers said in the letter that they believe the origins of the new policies to be a Law School administrator hired approximately six months ago, just before the changes took place.

The internal investigation comes as Local 615 and the University are negotiating a new contract for the custodial workers. But Langley said that, at this point, the investigation should not affect the coming discussions.

“They are taking this very seriously. We really appreciate that,” Langley said. “When we go to the [negotiation table], things should be pretty smooth.”

—Staff writer Mercer R. Cook can be reached at mcook@college.harvard.edu