JOHANNESBURG, DEC. 17 -- South Africa's Foreign Affairs Ministry confirmed today that, for a year and a half until last May, Chile's embassy in Pretoria sheltered a high-ranking Chilean intelligence officer who had been indicted in the United States for masterminding the 1976 car-bomb assassination in Washington of exiled opposition leader Orlando Letelier.

A senior ministry official said there were "no hard facts but only allegations" against the accused assassin and that it was not diplomatic practice to question assignments to foreign missions.

South African officials said Chilean Army Col. Pedro Espinoza Bravo, a onetime deputy chief of Chile's secret police, then known as DINA, served as an administrative counselor in the embassy as recently as May.

Espinoza reportedly was escorted back to Chile by a security detail to prevent him from surrendering to U.S. authorities and giving testimony that could link Chilean strongman Gen. Augusto Pinochet to the car-bombing. U.S. officials said he is in protective custody in Chile.

The South African Foreign Ministry was responding to a disclosure by the Washington bureau of South Africa's financial daily newspaper, Business Day, that Espinoza served in the embassy from December 1985 until last May and that another Chilean officer alleged to have been involved in political murders in Chile, Air Force Maj. Roberto Fuentes, served in Pretoria from March 1985 to August 1986.

When asked if the Foreign Ministry knew, when it gave Espinoza a visa, that he was under a 1978 U.S. District Court indictment for the murder of Letelier and his American assistant at Washington's Institute for Policy Studies, Ronni Moffit, the ministry official replied, "I doubt it. The head of mission is the one scrutinized. With juniors, you are simply told who these chaps are and you let them in. It's done throughout the world that way."

He added, "There are no hard facts but only allegations, and we have no reason to doubt the good faith of the Chileans."

A U.S. Embassy spokesman said that when Espinoza's presence became known, the State Department considered seeking his extradition, but did not act because of his diplomatic immunity. The spokesman said that as far as he knew, no complaints were made to the South African government about Espinoza. In any case, he said, Espinoza left the country soon after U.S. officials learned of his presence here.

Espinoza's abrupt departure came three months after a former DINA agent, Maj. Armando Fernandez Larios, surrendered in Washington and said he had participated in the plot to assassinate Letelier, a confidant of former Chilean president Salvador Allende.

Espinoza and his former chief at DINA, general Manuel Contreras Sepulveda, who was also indicted in absentia, had been identified as masterminds of the plot by Michael Townley, a U.S.-born DINA agent who was arrested by the FBI and confessed to planting the bomb that blew up Letelier's car at Sheridan Circle, on Massachusettes Avenue, on Sept. 21, 1976.

The U.S. Justice Department has been seeking to extradite Espinoza and Contreras since.

The Chilean Embassy in Pretoria issued a statement today condemning the news reports about Espinoza as part of an "international communist campaign" to rake up "obsolete information."

An embassy spokesman said allegations against Espinoza had been rejected by an "official court of inquiry" in Santiago in the late 1970s.