BUENOS AIRES, Dec. 7— The Government claims to have broken up a major kidnapping-for-ransom ring made up of active and retired police officers who some say have ties to groups that abducted suspected leftist extremists during Argentina's so-called dirty war.
In the last week, the police have announced the arrest and detention of 12 people they say were members of a gang that carried out a series of spectacular kidnappings over the last decade. All but one of the detainees have ties either to Argentina's intelligence service or its federal police. Many were, until their arrests, very senior officials in the police force. The gang is thought to have as many as 30 members.
On Sept. 23 the group abducted Mauricio Macri, the son of one of Argentina's wealthiest industrialists, and received a reported $2.5 million in ransom for his release.
The authorities said an investigation into the Macri case had led to the exposure of the kidnapping ring and its alleged leaders, Juan Carlos Bayarri and Jose Ahmed. Both are retired senior police officers.
In 1979, when a military Government was still in power, Mr. Ahmed was convicted of the kidnapping of a business executive, but was freed immediately after receiving an eight-year sentence.
Mr. Bayarri and two other retired police officials detained in connection with the inquiry served under the military juntas that ruled Argentina from 1976 thorugh 1983. Government officials have said they believe that the men were part of a group that kidnapped and killed left-wing extremists.
One suspected gang member who has been arrested, Juan Carlos Arza, was until recently the police commissioner of Buenos Aires and had previously served as the senior officer of the security force of former President Raul Alfonsin, who was elected in 1983 as part of the transition to civilian rule. Another alleged member was Raul Gonzalez, director of the telecommunications division of the federal police.
"In one sense we are pained that people on the force and retired officers have cast doubt on our institution," said Carlos Jacinto Gutierrez, deputy commissioner of the fraud division. "But on the other hand, it is a great satisfaction to eradicate criminal elements."
The Government said it first began breaking the ring when a disgruntled member who had not been paid his share of the Macri ransom began talking. Mr. Manzano said he believed that the group had been operating for at least 13 years, had been involved in five major kidnappings of executives and had collected millions of dollars in ransom. The police said they had recovered $2.08 million of the money.
This is not the first time the country's police have found kidnapping rings in their ranks. In 1987, five current and former police officials were arrested in the kidnapping and killing of three businessmen. Holdovers From 'Dirty War'
Nor is it the first time the country has had to face the fact that many police officers are holdovers from the days of the "dirty war" of the 1970's, when the right-wing military Government waged a fierce campaign against leftist guerrillas and opposition forces. More than 9,000 people disappeared. But the case illustrates how hard it is for a country with a tradition of military rule to bring its security forces under control.
Many officers who actively engaged in abductions and disappearances -- often on orders of their superiors -- under military rule are still serving in the Argentine police. But prosecuting these people for past crimes during the military regime is impossible since such crimes have been absolved under a series of pardons by both President Alfonsin and President Carlos Saul Menem.
While Mr. Manzano said no military officers took part in the kidnapping ring, President Menem said "it might be that some military were involved."