A U.S. grand jury here has discovered that a refrigerator originally purchased for use by the National Capital Housing Authority ended up in a Northeast Washington duplex owned by D.C. Recreation Department director William H. Rumsey.

The refrigerator is one of several that reportedly disappeared from a housing authority warehouse after being purchased for use in the agency's projects. At least three refrigerators have been located in the offices of a D.C. attorney and others still are being traced, according to federal and local investigative sources. More than $50,000 worth of refrigerators are missing, sources said.

Rumsey said yesterday that he has talked to investigators looking into the disappearance of the city-purchased property. he said he had "no idea as to the course that brought that appliance into one of my properties. It's just absolutely unbelievable."

Rumsey said he leaves the purchase of such equipment to a contracting firm, and that "those who take care of my property are just as honest as a dollar."

The refrigerator was found in a building at 642 Eighth St. NE that is owned by Rumsey and his wife. Neighbors said the refrigerator was removed from the building yesterday, apparently by law enforcement officers.

Investigators said yesterday that the investigation into the disappearance of approximately 200 refrigerators from a warehouse at 21 M Street NE still is in fairly early stages, and that there were no major investigative targets at this point. They also said that so far the investigation has been hampered by sloppy record-keeping involving both the purchase and the intended use of the appliances involved.

For example, the investigation said, it is unclear whether the refrigerators were stolen from the warehouse or improperly sold.

When the refrigerators were reported missing in March, D.C. Housing director Robert L. Moore said the problem was "either mismanagement or thieft" and that an extensive audit would be conducted to see what happened to the appliances. The audit still is under way.

The U.S. grand jury investigation appears centered on tracing the missing refrigerators before focusing on individual targets.

Investigators said the latest discovery of refrigerators was made in an office building housing a local attorney, who is being questioned about how the appliances got there.

Earlier, Fairfax County police arrested a D.C. man whose truck was carrying three of the refrigerators. Other refrigerators were traced to southern Virginia, where they apparently had been sold, soucces said.

Rumsey, who owns at least three other properties here, said he has told federal investigators he is willing to talk with them further about the refrigerator found on his property.

In March 1977, Rumsey was accused by several of his Recreation Department employes of abusing his authority by using maintenance workers from his agency to do repair on his home and rental properties. CAPTION: Picture, This is the home at 642 8th St. NE owned by Recreation Department director William H. Rumsey. one of the city's missing refrigerators turned up in the duplex. Rumsey expressed surprise at the revelation. By Fred Sweets - The Washington Post