MEXICAN OFFICIAL MAY HAVE COMPROMISED U.S. SECRETS.

Byline: Julia Preston The New York Times

Just days before he was detained on charges of collaborating with drug traffickers, the head of Mexico's anti-narcotics program was given detailed briefings on what the United States knows about Mexico's cocaine cartels, administration officials disclosed Wednesday.

The officials, speaking on condition of anonymity, said they had begun an immediate ``damage assessment'' to determine if secret information had been compromised or if U.S. drug informants have been placed in danger. One administration official said Wednesday night that the briefings had included ``really sensitive stuff.''

Another administration official said the United States was especially concerned about possible threats to the informants who provided information to American drug and intelligence officers.

``If the information about them is closely held and only four people know about it, the way they work down there they'll kill all four people,'' this official said.

U.S. officials acknowledged they had no early warning that Gen. Jesus Gutierrez Rebollo, the former commissioner of the National Institute to Combat Drugs, was under suspicion of doing business with one of Mexico's most powerful drug lords.

Mexican authorities confronted Gutierrez with the accusations against him, forced his resignation and detained him Feb. 6, but U.S. officials said they did not learn of the charges until Tuesday, when they were announced by Mexican authorities.

``This points to a major intelligence community failure,'' one U.S. official said. ``He was detained since February 6 and we didn't know it. We had no idea.''

At a news conference Tuesday night, Defense Minister Enrique Cervantes Aguirre disclosed that Gutierrez had received gifts, payments and real estate from the cartel controlled by Amado Carrillo Fuentes, one of Mexico's most ruthless and aggressive drug lords, and had provided protection to cocaine shipments for as long as seven years.

Gutierrez, along with two of his top aides, was remanded Wednesday to a maximum security prison near Mexico City to face charges of racketeering and aiding the traffic of cocaine, Attorney General Jorge Madrazo Cuellar said. The general will also face a court-martial at which top military commanders have suggested he may be tried for treason.

The events leave Mexico's drug program in disarray only two weeks before President Clinton is expected to certify to Congress that Mexico is making significant strides in its drug effort.

As head of a special, closed agency set up in 1993 to insulate drug operations from the corruption of the civilian police, Gutierrez was privy to Mexico's most secret counter-narcotics operations and had access to the most confidential intelligence Mexico has gathered about its cartels.

Gutierrez traveled to Washington in late January with Madrazo to discuss the transfer of U.S. helicopters to Mexico for counter-narcotics operations. Gutierrez was treated to closed briefings by White House, Drug Enforcement Administration and intelligence officials, administration officials said.

One official said the Clinton administration is now trying to determine ``what we gave them, what format it took, whether a source could be identified by the way we shared the information or if methods were exposed.''

The arrest on drug charges of the officer who had been named only two months earlier to lead the drug agency left U.S. officials wondering who in Mexico, if anyone, could be trusted to carry on the fight against a flood of narcotics flowing from Colombia across the border into the United States.

Mexican leaders, struggling to be optimistic, cited the general's arrest as an example of President Ernesto Zedillo's determination to combat narcotics traffickers even at the risk of exposing top-level officials.

Armed forces commanders, however, made it clear they are convinced that Gutierrez took part in a long-term scheme to enrich himself by working with the Carrillo Fuentes operation, believed to be the dominant cartel in Mexico.