MEXICO CITY, May 23 -- Some of Mexico's most prominent anti-drug operations of the past year were undertaken at the behest of Mexico's biggest drug baron, who had enlisted corrupt generals in his war against a competitor, military officers have testified in secret court proceedings here.

The testimony, which came in parallel court-martial and criminal inquiries, shows how drug corruption has spread more widely through Mexico than previously thought, and offers a richly detailed account of how traffickers have undertaken to suborn even Mexico's highest-ranking leaders.

The testimony also raises questions about efforts by the Mexican and American Governments to rely on the military in the fight against drugs rather than on the police, which have already been tainted by corruption.

The new details are part of the case against Gen. Jesus Gutierrez Rebollo, who was arrested in February on corruption charges.

According to an 1,100-page record of the proceedings, at least 14 army captains, lieutenants and noncommissioned officers are cooperating with military and civilian prosecutors in their cases against General Gutierrez.

The officers testified that many of the manhunts, house-to-house searches and other efforts hailed by the Government as evidence of its cooperation in the war on drugs were collaborative ventures.

Units of the Mexican military, they said, worked closely with eavesdropping experts and gunmen working for Amado Carrillo Fuentes, a drug trafficker who helped pay for the attacks on his rivals, the officers said.

These operations, the officers said, included the army's wide sweep through Tijuana in March 1996, a nationwide dragnet last fall for the killers of a police commander and the navy's seizure of a cocaine-laden freighter in January.

The arrest of General Gutierrez in February came just as the United States was weighing its annual certification of Mexico's full cooperation in the drug war. The arrest drew scathing criticism in Congress as a revelation of the extent of corruption, even as American and Mexican officials portrayed it as an instance of Mexico's determination to clean up the military.

President Ernesto Zedillo, in an interview on the eve of President Clinton's visit here early this month, called the military ''the best people that Mexico has, in spite of Mr. Gutierrez Rebollo.''

But officers have named at least four generals, in addition to General Gutierrez, as collaborators with Mr. Carrillo Fuentes.

In one case, the trafficker was said to be using an air base commanded by one of his military associates to land drug planes. After another general died in an air crash in September 1995, Mr. Carrillo Fuentes and his wife were photographed at his funeral, according to the testimony.

By lifting the curtain on the inner workings of the Mexican Army, the court-martial is rocking an establishment that the American academic Roderic Ai Camp has called ''the most closed military in the world that I know of.''

General Gutierrez, who for seven years before his arrest was the commander in five central states and, starting in December, Mexico's anti-drug czar, has added to the fireworks. He has denied the charges against him and has argued in documents filed with the court that he kept the Secretary of Defense, Gen. Enrique Cervantes Aguirre, and his predecessor informed of all of his anti-drug efforts, including his dealings with Mr. Carrillo Fuentes's organization.

And apparently threatening to come up with even more sensational revelations, the general has reported that a trafficker whom he detained and turned into an informer accused ''senior officials of the Mexican Government as protectors and members'' of a Tijuana drug cartel.

Asked for comment about the testimony, an officer in the Defense Ministry's Office of Social Communication, who identified himself as Lieutenant Colonel Aguilar, said only, ''Our institution has no point of view on these proceedings, and so we have no comment.''

Since the arrest of General Gutierrez, the allegations of drug corruption have come to encompass other senior officers.

In March, the Defense Ministry announced the arrest of Gen. Alfredo Navarro Lara, accusing him of offering a $1-million-a-month bribe to the general who is leading anti-narcotics efforts in Tijuana. The army say he offered the bribe on behalf of the Arellano Felix organization, Mexico's second-largest drug cartel.

For several years Mr. Carrillo Fuentes and the Arellano Felix brothers have been pursuing a murderous rivalry that has come to divide Mexico as fully as the 1980's vendetta between the Medellin and Cali cartels did Colombia.

General Gutierrez, who is 63, rose from second lieutenant to division general in just 31 years, promotions that usually take at least 35 years. His appointment as commander of Military Region No. 5, in Guadalajara, Jalisco, and encompassing four surrounding states, capped what associates have called a brilliant military career as a cavalry officer, garrison commander and professor at Mexico's Senior War College.

Mr. Carrillo Fuentes, the testimony indicates, used General Gutierrez's love of horses as an early path to winning his cooperation.

The father of one of Mr. Carrillo Fuentes's top associates owned a farm adjacent to the base in Guadalajara commanded by the general, and starting in 1995, General Gutierrez began to buy alfalfa from the father, who soon began sending sweet corn and tomatoes as gifts.

Those early offerings paid off in late 1995, when gunmen working for the Arellano Felix organization ambushed the farmer's son and granddaughter, wounding them both.

After that attack, the son, Eduardo Gonzalez Quirarte, limping on crutches, visited General Gutierrez at his downtown Guadalajara offices and offered information on the Arellano Felix organization, the general's subordinates testified. At that time, Mr. Gonzalez Quirarte was not widely known as a drug trafficker.

From that beginning grew ties that went far beyond the normal relationship between an investigator and his informant: the general became the instrument of one drug organization against another and, prosecutors assert, he received a variety of gifts.

Immediately after Mr. Gonzalez Quirarte volunteered his services, the general ordered a team of his plainclothes officers to Tijuana, where they worked with Mr. Gonzalez Quirarte and others to spy on the Arellano Felix operations.

These actions culminated in March 1996 in a army sweep by hundreds of soldiers through several Tijuana neighborhoods. The raid was seen as one of Mexico's most important anti-drug operations last year.

In testimony, the general's aides have said that in Guadalajara he adopted a lavish style, assigning soldiers as cooks, drivers and gardeners not only to his wife's household but also to two lovers' homes. General Gutierrez acquired a fleet of cars and armored Jeeps and purchased two thoroughbreds.

Some of the general's subordinates testifed that they were bewildered by their commander's new alliance with a drug-trafficking organization.

But over the following months, the general's associates got an inside look at the Carrillo Fuentes organization -- luxury homes in Guadalajara and Mexico City where Mr. Gonzalez Quirarte's aides used sophisticated eavesdropping equipment to scan hundreds of phone calls. They saw that Mr. Gonzalez Quirarte traveled in a convoy of 18 armored Land Cruisers, Jeeps and sedans, guarded by dozens of men with credentials issued by Mexican military intelligence, according to the testimony.

The aides testified that they discovered that Mr. Carrillo Fuentes's influence extended elsewhere in the army.

During 1996, the aides arrested an Air Force flight specialist who, under interrogation, acknowledged that he had been guiding the trafficker's planes into Guadalajara airports. Other testimony indicates that at least two generals deployed at Base No. 5 in the city were intimate friends of Mr. Carrillo Fuentes.

After Arellano Felix gunmen killed one of General Gutierrez's closest intelligence aides last July, and later assassinated police commanders in Tijuana and Mexico City, the army's cooperation with Mr. Carrillo Fuentes deepened.

General Gutierrez's subordinates, working with Mr. Carrillo Fuentes's eavesdroppers and gunmen, detained and interrogated dozens of suspected Arellano Felix associates, the testimony indicates.

Several army officers described to prosecutors how Mr. Gonzalez Quirarte and other traffickers participated in questioning the suspects.

Before one joint operation, the traffickers briefed one of the general's subordinates, showing him a file of reconnaissance photos of Arellano Felix associates and their residences, as well as tape recordings of telephone conversations the traffickers had intercepted, the testimony indicates.

For all this cooperation, Mr. Carrillo Fuentes expressed his gratitude, providing General Gutierrez with nearly a dozen armored vehicles, delivering monthly payments to his personal secretary and signing over a Guadalajara restaurant to another of the general's top aides. However, the Government has not yet produced evidence that the general accumulated a great fortune.

Last October, the trust was so high between General Gutierrez and the Carrillo Fuentes organization that the traffickers delivered encrypted cellular phones that allowed Mr. Carrillo Fuentes and his aides to talk freely with the general, his driver and other military officers, the testimony indicates.

In December, when General Gutierrez was named to head Mexico's top anti-drug agency, his first reaction was to call Mr. Gonzalez Quirarte and ask the trafficker to arrange a Mexico City apartment for a young lover.

Mr. Gonzalez Quirarte agreed. When the general's driver went to the trafficker's Mexico City residence to pick up the keys, Mr. Gonzalez Quirarte introduced him for the first time, face to face, to his boss.

''This is Amado Carrillo Fuentes, the Lord of the Skies,'' Mr. Gonzalez Quirarte told the driver, the testimony indicates. ''Feel proud. Many would like to meet him, but you are among the few who've succeeded.''

The testimony leaves in dispute why General Cervantes, the Defense Minister, ordered General Gutierrez's arrest in February. Army prosecutors say that General Gutierrez's driver phoned military authorities on Feb. 6, offering to inform on his boss. But General Gutierrez's lawyers insist that the Defense Secretary ordered the arrest after General Gutierrez protested cancellation of an operation intended to detain members of the Arellano Felix organization in Tijuana.

Days before General Gutierrez's detention, Mr. Gonzalez Quirarte told the general's driver that he and Mr. Carrillo Fuentes were planning to leave Mexico. A week later, the driver received a call from the two traffickers, who claimed to be phoning from Russia. Their current whereabouts are unknown.

''They said they couldn't work here because they hadn't been able to cut a deal with the authorities, referring to some lawyers representing the army's general staff,'' the driver, an army lieutenant, told the court. ''But they said that once they'd arranged matters with the authorities, they were going to bring in cocaine by the boatload, 30 tons at a time.''