Relying on government promises of a new identity to protect him, a young Cuban alien involved in drug traffic on the East Coast became a federal informant and in 1973 gave key testimony against major drug violators.

Today, after helping jail people who he says would kill him in revenge for his testimony, the Cuban still lacks the U.S. citizenship and full documentation he says U.S. agents guaranteed.

Embittered and afraid, the Cuban-who used the fictitious name "Orlando" in dealing with a reporter-has sued the United States for that new idendity and the chance to break with the past.

Living in Northern Virginia with his foreign-born wife and children, Orlando has only a name and a false driver's license furnished by the government in a relocation effort called "a program of broken promises" by one U.S.official.

"They think informants are like pens. You use them until the ink runs out and then you throw them away. That's their philosophy," said Orlando in a recent interview at his suburban home.

Orlando was a valuable government witness who provided testimony that led to the conviction of several underworld figures, and was promised a new identity, acknowledged an official og the U.S. Marshals' Witness Protection Service, which adminsters the program.

But the official denied that Orlando or any other witness ever has been promised U.S. citizenship. The agency lacks authority to make such an offer, the officail asserted.

In any event, Orlando's two prior convictions for drugs and tax evasion render him ineligible for citizenship regardless of the name he uses, the agency said.

Officials admit that the use of aliens presents a "sticky question" regarding new identities without citizenship. But they emphasize that aliens represent less than 10 percent of those in the program.

Most former informants and witnesses adjust well to ther new identities and are free from their criminal past, he said.

About a dozen suits similar to Orlando's have been filed against the service recently, according to a spokesman for the marshals.

The program, which was set up in 1971 under the Crime Control Act, was intended to provide about $900 a month living expenses, protection to those who testified for the government, and a new identity supported by documentation such as a birth certificate, driver's license, Social Security card, and military, academic and medical records.

A Senate subcommittee that investigated the program this year found it was not taken seriously enough by the marshals, was poorly run, and that promises were made that could not always be kept, according to a subcommittee staff member.

"It's a program of broken promises," siad one source within the marshal service who has worked with the program since its inception. "The program simply can't produce what it's supposed to produce."

Thirteen of the 2,700 witnesses who have gone through the program have been killed, a spokesman for the U.S. Marshal Service acknowledged.

A stocky, 5-foot-10 man with ink-black hair and a sometimes nervous glance, Orlando said he decided reluctantly to speak to a reporter.

"If you blow my cover I got to pack and move. They would have a hit man here in a week. No question in my mind," Orlando said.

In his lawsuit, filed in the federal court for the Southern District of Florida, Orlando seeks to compel the government to provide him with what he says he was promised-a "whole new identity,"including citizenship, a new birth certificate and a passport.

He also is suing for damages for the "fear, tension and frustration" that he claims have eaten into his sleep, driven his wife to a suicide attempt, and torn his family apart.

"I have been going through hell, waiting, waiting, waiting. I don't have any place to go," said Orlanco. "There is no new life. Where is the new identity they promised me?"

"I feel great empathy for him, but he's received everything he's entitled to. He has been treated quite fairly. He has a life here. He's on his feet.His life with crime is behind him," said Jerry Auerbach, an attorney with the marshal service who is working on the suit filed by Orlando.

Orlando said that he "put people in jail for 18 and 19 years. Some were millionaires. With that kind of money they can hit me. There's no question in my mind."

But by his own account, Orlando is no stranger to high risks and violence. At 17, he was sentenced to two years in Cuba's Matanzas Prison for arson and theft, he said, but later escaped.

Once in the United States, Orlando entered the world of drug smuggling, which he claims he did to raise money to buy arms for use against Castro. But after the Bay of Pigs, invasion seemed far off if not impossible so he went to work for profit, he said.

In June 1970, he was arrested by Drug Enforcement Administration agents in New York. It was then that he forged a relationship with the DEA that was to last for four long and perilous years. "I became an informant, a snitch," he said.

Accoriing to copies of Justice Department records in his possession, he infiltrated a ring of Cuban drug smugglers that took him from Miami to Los Angeles and Mexico City and New York.

A 1971 letter signed by DEA regional director William J. Durkin commends him for "providing important and valuable assistance" in prosecuting "large scale traffickers in the Southern District of New York."

Since then,Orlando and his wife and large family of school-aged children have moved from place to place.

It has been difficult for the youngsters. His 8-year-old child does not know what his father did for the government, why he has moved 16 times and gone to four different schools, or why he has had to break off so many burgeoning friendships and not been allowed to correspond with them.

"There is always the threat," says Orlando's wife. "If they go to jail for 10 years because of [Orlando], maybe one will forget, or two, but some will not."