FBI agents and D.C. police detectives yesterday arrested four men in connection with a reported extortion scheme in which three of the suspects allegedly posed as police officers, accused a Silver Spring man of committing a homosexual act and then demanded $10,000 to dismiss the matter.

The arrests were made after the victim, a federal government employe, told the FBI early yesterday of the alleged blackmail scheme, which the victim said, began in a restroom at the Mayflower Hotel in downtown Washington at noontime last Thursday.

A sworn statement by an FBI agent filed in U.S. District Court yesterday said a man approached the victim in the hotel restroom, made lewd gestures, remarks and body contact and then displayed a silver badge and said, "That's all I need, you are under arrest." He then turned to a second man in the restroom and said, "You saw that, didn't you, I am going to take this guy and interrogate him . . ." the statement said.

The victim was then led by the first man across 17th Street NW into the lobby of the National Geographic Building where he was questioned about his identity, occupation, salary, bank accounts and any previous arrest record, FBI Special Agent James P. Donlan said in the statement.

After the victim said he had no arrest record, he produced a drivers's license that was then taken by the second man who left the area, according to the statement. When the second man returned, he told the first man "he checks out clean," and the victim was released "without charging him for a crime," the statement said.

On Monday, however, the victim received a telephone call at his office from a man who said he was "one of the officers who arrested you." The man agreed to a meeting at an undisclosed location to look at photographs of other criminals and discuss another "problem," according to the statement.

The caller turned out to be the second man at the Mayflower, the statement said. He told the victim that he and the other "officers" were in "hot water" because they had not arrested the victim the previous Thursday. A third man, who displayed a gold badge and said he was the "lieutenant," joined them, explained how arrest records are computerized and said he and the other officers were under investigation because the "computer" showed an arrest that Thursday but that no defendant had been taken into custody.

According to the statement, the lieutenant told the victim he was about to retire to a job in private industry, that he did not want any "problems." He then demanded $10,000 to "tear up the subpoena" for the victim's arrest and purge the record of the case. When the victim said he had only $2,500, the lieutenant agreed to accept that amount, the statement said.

The FBI investigation began at 6:30 a.m. yesterday when a lawyer friend of the victim called the FBI field office in Washington and said he thought his friend was being blackmailed by men posing as police officers.

FBI agents recorded a telephone conversation at 9:35 a.m. yesterday between the victim and a man who identified himself as the "lieutenant," cautioned the victim to "relax," and suggested the victim produce $5,000, instead of $2,500 and bring it to the lobby of the Sheraton Carlton Hotel at 11 a.m., the statement filed in court said.

Federal agents and District police detectives, who had joined in the investigation, then arranged to rendezvous with the victim at the Carter Barron Amphitheater on upper 16th Street NW, where they planned to give him a tape recorder and an amount of "flash" money to be shown to the "officers," sources said yesterday.

As the agents followed the victim from his Silver Spring home into the District, they observed a late model Lincoln Continental, occupied by four men, in the vicinity of the victim's home and later near the amphitheater, the FBI's agent's statement said.

District police detectives arrested three men in the car, parked at 16th and Upshur Streets NW, who were identified by the victim at the scene as the 'officers." Police confiscated a notebook containing the victim's address, a black wallet-type folder containing a police badge and police identification from 12 states and 24 cities.

The three men arrested in the car were Loy Franklin Dove, 46, of Laurel; Thomas William Tavenner, 46, of Pepperell, Mass., and Francis Bernard Donahue, 56, of Jeffersonville, Ind. After a hearing yesterday, U.S. Magistrate Arthur L. Burnett released Dove on $5,000 unsecured bond and ordered that Tavenner and Donahue be held on $25,000 and $10,000 bonds respectively.

The fourth man, Tavenner's son, Mark Clarence Tavenner, 23, of Villerica, Mass., who was arrested after he was observed by the police at the amphitheater rendezvous, was released to the custody of an uncle, who lives in Northwest Washington.

All four men were charged with interstate travel in aid of racketeering, which carries a penalty of five years in jail, a $10,000 fine or both.