MIAMI (AP) _ The convicted cocaine smuggler whose case led to a Cuban drug scandal and execution of four Cuban officials has given U.S. officials details of at least four other drug rings involving ranking figures in Cuba's government, prosecutors said Monday.

The attorney for smuggler Reinaldo Ruiz said Ruiz had implicated Cuban President Fidel Castro and his brother Raul in cocaine trafficking, but prosecutors would not confirm those names.

At Ruiz's sentencing hearing Monday, Assistant U.S. Attorney Thomas Mulvihill asked for a reduced sentence because of Ruiz's substantial assistance to the government.

Ruiz ''laid out the involvement of the Cuban government in drug trafficking ... detailing a number of other narcotics trafficking groups led by high Cuban officials,'' the prosecutor said.

Although Ruiz could have faced a life term, U.S. District Judge Thomas C. Scott sentenced Ruiz to 17 years and fined him $1.1 million; Ruiz, 51, will be eligible for parole in about 11 years. Scott said he could reduce the sentence further if Ruiz continues to testify.

Ruiz's attorney, Fred Schwartz, told the judge the government had apparently leaked information from Ruiz's interrogation to the Cuban government, aborting possible indictments of other Cuban leaders in order to smooth diplomatic relations with Cuba.

''We may have had the ability, had it not been thwarted by the information given by the government, to indict the defense minister and the prime minister of Cuba,'' said Schwartz, referring to Raul and Fidel Castro.

Mulvihill said information could have come from videotapes of the case that had been released at previous hearings and added that Ruiz had a tendency to talk with family and friends about what he was doing.

Ruiz took the stand briefly, saying he wanted to make up for the damage he had done through his drug smuggling.

''I am willing to testify, cooperate, to go to any kind of extent ... even on my own expense,'' Ruiz told the judge.

Ruiz pleaded guilty in March to heading a cocaine-smuggling ring that shipped 1,000-pound loads of cocaine into the United State via a Cuban air force base at Varadero. His son, Ruben Ruiz, and girlfriend, Ligia Cruz, also pleaded guilty and are awaiting sentencing.

Ruiz, a Cuban exile, had set up a smuggling ring that handled everything from getting Cubans out of their homeland to bringing Puerto Rican lottery tickets to the United States.

He eventually made contact with a cousin in the Cuban military who introduced him to many of the officials who have been arrested or executed.

Fidel Castro has acknowledged that revelations from the case, which he said matched information from Colombian sources, prompted the investigation that led to the June arrest and later execution of four top Cuban officials, including decorated war hero Maj. Gen. Arnaldo Ochoa Sanchez.

More top Cuban officials, including fired Interior Minister Brig. Gen. Jose Abrantes Fernandez, have been arrested since, and the military has been purged.

To stop drug trafficking, Cuba has also declared that any plane flying over the island outside of approved corridors will be shot down.

The U.S. State Department has cautiously welcomed the moves, saying they could lead to increased cooperation with the Cuban government to interdict drug smugglers.

But the U.S. Customs Service has reported that, even since the crackdown, drug planes have made air drops to smugglers' boats in Cuban water and have ducked into Cuban air space to evade U.S. drug patrols.

U.S. officials have pointed out that Cuban Vice Admiral Aldo Santamaria Cuadrado, who served on the tribunal that recommended Ochoa's trial and execution, is himself is under indictment in a 1982 Miami drug case.

And Castro allegedly was an intermediary between the Medellin Cartel of cocaine traffickers and Panama's military ruler, Gen. Manuel Antonio Noriega, to smooth over a drug dispute, according to Noriega's 1988 indictment here.