After months of denying the existence of on-the-job harassment in the Harvard police department, the University yesterday moved to investigate charges made by guards against their supervisors.

General Counsel Margaret H. Marshall yesterday said two members of her former law firm will investigate allegations made by seven guards last spring.

A. Hugh Scott, head of the litigation department at Choate, Hall and Stewart, and James A. Ring, director of investigative services at the firm, will speak with all security guards who wish to be interviewed, Marshall said.

"In order to perform my review, I needed to obtain factual information," said Marshall, who was senior partner at Choate before coming to Harvard in November. "All of the security guards have been invited to be interviewed."

Marshall declined to say how or whether Scott and Ring would be compensated for their investigation. Harvard has more than 100 security guards.

Marshall said she had met several times with Police Chief Paul E. Johnson to discuss the handling of the investigation. Several guards and police officers have criticized Johnson's handling of the harassment complaints, some accusing the chief of retaliating against guards who brought grievances.

Marshall also shrugged off guard criticisms that her office is incapable of performing an adequate investigation of the unit. An earlier investigation--performed last spring by then-General Counsel Daniel Steiner '54--failed to interview guards, and University Attorney Frank J. Connors this fall accused security guards of using charges of discrimination as a crutch.

"Chief Johnson and I are committed to providing a working environment that is free of discriminatory practices or the perception of any discriminatory practice," Marshall said.

The hirings came the same day a former guard, Juan Figueroa, said he may file suit against the University.

Richard H. Spicer, a local attorney, confirmed last night that he had been hired by Figueroa. Spicer refused to comment further, citing attorney-client privilege.

Figueroa, who is Hispanic, said he was fired last April 6 by Manager of Operations for Security Robert J. Dowling after being found of his post.

Figueroa acknowledged last night that he had been off his post, but said the punishment was serve because he had never been disciplined before in nearly four years on the job. Figueroa said he believed the firing was ethnically motivated.

Marshall refused to comment on whether her office had been contacted by guards or their attorneys.