When the town of Fairmount Heights sought to add a police officer and drug-sniffing dog to its one-man department recently, Mayor Ruth Brown turned to Prince George's County for help.

Brown asked the county police department to loan the town an officer to patrol with his dog. There was one caveat, however. The officer, Brown said, had to be black.

"I made the request for a black officer because the town is predominantly black," said Brown. "We thought that the officer would fit right into the town's racial base."

Prince George's County police officials said yesterday that they had discussed several options with Brown but told her they could not select an officer based on race. "We explained to the mayor that we could in no way limit any kind of contractual agreement to officers of only one race, although we understood her concerns," said Lt. Col. Robert Phillips.

Darryl A. Jones Sr., president of the Fraternal Order of Police Lodge 89, yesterday called the request by Brown absurd.

"I don't think that race has anything to do with the capability of a K-9 team," said Jones, the first black officer elected to lead the police union. "The request reeks of racism."

Phillips said the department subsequently made informal inquiries among its five black K-9 officers to see if any was willing to work part time for the town, a request several officers said was misinterpreted.

The black officers refused to participate, telling their commanders that they believed the request was racially divisive, said several officers who spoke on the condition that their names not be used.

"The five black K-9 officers on the department were asked if they would work for Fairmount Heights and they were the only ones who were asked," said an officer familiar with the situation. "They said no, that if everyone couldn't work, they wouldn't do it."

Brown is active in the local branch of the NAACP and her husband, Richard Steve Brown, was an outspoken critic of the Prince George's County police during his tenure as local NAACP president. Ruth Brown said she did not believe her request had racial implications.

"We don't have a race problem up in Fairmount Heights because we're all black," said Brown. " . . . It's a black town and the use of a dog, within the confines of a small town, will have its own getting used to . . . and naturally, it would be an easier process if the officer were black."

Although activists and officials say the county, which is 50 percent black, has made significant progress in race relations, Brown's request underscores the fact that tensions still exist. A poll taken by The Washington Post last summer, for instance, indicated that while 72 percent of county residents rated the Prince George's police department as good or excellent, there is a lingering distrust of local law enforcement among some black residents.

Brown said that the town had received a state grant to expand its drug enforcement and planned to use the money to hire a police officer, buy a car and a drug dog. Brown said that she thought the most efficient tack would be to ask the county to allow its officers to work for the town in their off-duty hours.

The town now is exploring other options, Brown said.