Two detectives have been temporarily transferred from the D.C. police department's homicide squad following allegations by the U.S. attorney's office that the initial investigation of a fatal shooting by police was substandard, according to police sources.

The transfers apparently were sparked by a "scathing" letter written in April to D.C. Police Chief Maurice T. Turner from U.S. Attorney Joseph E. diGenova, sources said. They said the letter implied that the investigation was deliberately sloppy and asked that the case be reexamined.

On Thursday the detectives involved in the investigation, Russ Drummond, 38, a 17-year veteran of the force, and Jeff Greene, 39, a 16-year veteran, were temporarily transferred to the department's burglary branch while homicide officials investigate the allegations.

The police shooting occurred June 2, 1984, when Gregory Brown, 29, allegedly grabbed a police officer's service revolver during a scuffle and fled into a house on S Street NW near North Capitol Street, then emerged and fired several shots at a police barricade.

Brown, whose body was later found to contain traces of PCP, was shot by police seven times, including three times in the back at close range.

There were television reports Monday night of the transfer of Greene and Drummond. One of the reports stated that Brown had been shot in the back of the head at close range, that the homicide detectives did not disclose any close-range wounds, and that a grand jury was investigating the possibility of a "police cover-up."

Charles H. Roistacher, a spokesman for the U.S. attorney's office, yesterday called the television reports "very misleading" and "very unfair to the officers.

"There is not a Superior Court grand jury investigation of obstruction of justice" in the case, Roistacher said. He said, however, that as in the case of all police shootings, evidence will be presented to the grand jury to determine whether the shooting was justified.

In addition, police sources said that Brown was not shot in the back of the head, and that the detectives had, in fact, mentioned in a report written soon after the incident that the medical examiner should be aware of the possibility of close-range wounds.

According to police sources, the U.S. attorney's office was not satisfied with the initial investigation into the death, and the case was sent back to the homicide branch because it was "incomplete."

At the same time, U.S. Attorney diGenova wrote a four-page letter to Police Chief Turner that was highly critical of the quality of the investigation and questioned its integrity, sources said.