Allegations of at least one mercy killing by a former nursing staff member at Maryland General Hospital here are under investigation by the Baltimore City state's attorney's office.

Prosecutors and Baltimore police were called in by hospital officials after rumors of a possible mercy kiling reached the hospital administration and an employe resigned the same day, according to Assistant State's Attorney Howard Gersh.

No current employes are under investigation, Gresh said.

The death of one male hospital patient who had been connected to a respirator is currently "the only death really under investigation," according to Dr. Anne Dixon, an assistant medical examiner.

Dixon said she was helping police and prosecutors interpret the medical records of this patient, whose name or ailment she refused to reveal.

The death March 8 of a female patient, who was also was connected to a respirator, had been under investigation, Dixon said. But she said that this death was no longer under suspicion as a mercy kiling.

Baltimore police spokesman Dennis Hill confirmed that the name of the suspected employe has been turned over to the Maryland Nurses Board of Examiners for possible disciplinary proceedings. The board has jurisdiction over practical and registered nurses, but its hearings and records are secret unless there is a guilty finding in a case.

Assistant Attorney General Stephen J. Sfekas refused to comment in any way on the Maryland General case.

Gersh, who is chief of the Baltimore prosecutor's violent crimes unit, said homicide detectives, with the help of medical examiners, are combing the records of patients who have died at the hospital's special care unit, where the alleged mercy killingswere said to have occured. They are also interviewing hospital staff members who were sources of the original mercy killing rumor, he said.

"Employes had become suspicious of some coworkers and we are looking at the case in this way," Gersh said. "But we have not talked to anyone who said he actually witnessed it [a mercy killing]."

Yesterday, department heads at the 350-bed hospital were told of the investigation in a meeting and letters were handed out to all staff members notifying them of the investigation, according to Clark Jeunette, hospital spokesman.

The mimeographed letters, signed by hospital administrator Barry Bowers, said that prosecutors were investigating "the possibility that a former member of the hospital's nursing staff may have been responsible several months ago for the interference with life support of one or more terminally ill patients."

The letter stated that no current employes were under investigation and said, "I assure you that the administration's principal concern and interest is that of the hospital and its employes . . ."

Jeunette said that the announcement of the investigation had not adversely affected the staff and that yesterday "was like any other working day" at the 97-year-old institution, which is a teaching hospital affiliated with the University of Maryland.

Several employes leaving the hospital late yesterday said they and their colleagues were "shocked" and "surprised" when they learned of the investigation in the staff letter or through newspaper articles that appeared yesterday afternoon.

"We're too upset to talk about it," one young nurse said.