Washington-Two Cuban diplomats expelled by the United States this summer were intelligence agents who were trying to recruit Cuban Americans as spies, the State Department disclosed in a letter released Monday by Rep Dante Fascell, D-Fla.

Bienvenido Abierno, then acting chief of the Cuban Interests Section, and consular officer Virgilio Lora "were considered to be intelligence agents engaged in activities inconsistent with their diplomatic functions," wrote J. Edward Fox, assistant secretary of state for legislative affairs, in a letter Friday to Fascell.

At the time of their expulsion last July, the two Cubans were not publicly identified as intelligence operatives.

Lora’s activities were outlined last month in a Radio Marti program in which defector Florentino Azpillaga Lombard, a former major in the Cuban intelligence service, said Cuban Americans in South Florida were an espionage target of the Fidel Castro government.

On the same program, former Miami newsman Nirso Pimentel described Lora’s unsuccessful attempt to befriend him as a prelude to recruitment. The State Department letter said Pimentel’s account was "consistent with the assessment by U.S. agencies concerned."

The expulsion of Abierno and Lora was originally cast by the State Department as retaliation for Cuban harassment of U.S. diplomats in Havana. Cuban state television had aired a series called The CIA War Against Cuba, in which it accused four diplomats assigned to the U.S. Interests Section of being CIA agents.

It has since been learned that the Cuban television series may itself have been a response to Azpillaga’s defection. Suspecting that Azpillaga would reveal the names of Cuban double agents who had contact with U.S. officials in Havana, the Castro government apparently decided to unmask its own agents. The televised stories of the double agents may have been intended as a pre-emptive propaganda strike to take luster away from any declarations by Azpillaga.

The State Department letter followed inquiries by Fascell about Azpillaga’s allegations.

In a separate response to Fascell, the Justice Department said there is little it can do to prosecute Cuban agents under diplomatic cover in the United States.

"Most Cuban officials assigned to [U.S. posts] enjoy full diplomatic privileges and are therefore generally immune to prosecution under U.S. laws," Assistant Attorney General John R. Bolton wrote Fascell, chairman of the House Foreign Affairs Committee.

In a statement that accompanied release of the letters, Fascell criticized the Reagan administration for not making Azpillaga available for interviews by the independent, nongovernment media, while allowing access to Radio Marti.

"Radio Marti is a U.S.-government operated radio station and news service," Fascell said. "It should not be granted special privileges not available to domestic news media such as exclusive interviews with defectors or others under the control of the government. If the defectors are willing to make their charges public, they should be willing to make them to anyone who is interested."

Richard Carlson, the Voice of America director responsible for Radio Marti, has said that Azpillaga specifically requested an interview.