LOS ANGELES, MAY 25 -- Drug Enforcement Administration officials in Washington directly authorized payment of $50,000 and expenses to a group of Mexicans willing to kidnap a Guadalajara doctor allegedly involved in the murder of a DEA agent and bring him to the United States, a DEA agent testified today.

Hector Berrellez, an agent based here, said DEA deputy director Pete Gruden authorized the operation only after failure of negotiations with representatives of the Mexican attorney general to trade gynecologist Humberto Alvarez Machain for a Mexican fugitive in the United States.

The testimony on the U.S. reward for the abduction -- $20,000 of which has been paid -- was given in a U.S. District Court hearing here on a motion to dismiss charges against Alvarez Machain on the grounds of misconduct by U.S. agents.

The doctor was arrested when his plane landed in El Paso April 3, and he was charged with participating in the 1985 torture-murder in Mexico of DEA agent Enrique "Kiki" Camarena. Alvarez Machain and his attorney have charged that at least one DEA agent helped to kidnap him from Guadalajara and that he was shot seven times in the foot with a stun gun to ensure his cooperation.

Antonio Garate Bustamante, a former Mexican drug agent working for the DEA, said he organized the abduction by telephone from the United States and told friends in Mexico, including some officers of the Mexican Federal Judicial Police, that they would be rewarded after the doctor reached U.S. soil.

He said seven Mexicans involved in the abduction and as many as 16 of their wives and children are living in the United States for their own protection. The seven have been paid as much as $42,000 in living expenses since the operation, he said.

Alvarez Machain's attorney, Robert Steinberg, questioned Berrellez and Garate Bustamante about arrangements for the abduction but sought no testimony about physical harm to his client.

Steinberg, well known here for his role as a defense attorney in the case of Vicky Morgan, slain mistress of the late industrialist Alfred Bloomingdale, experienced difficulty framing his opening questions. U.S. District Judge Edward Rafeedie took over most of the questioning of Berrellez and Garate Bustamante.

Federal prosecutors have denied allegations that a DEA agent assisted in the abduction and that Alvarez Machain was tortured. Even if the doctor was kidnapped, prosecutors argued in a brief submitted before the hearing, "that fact is irrelevant to the ability of this court to go forward on the charges against him."

Alvarez Machain testified that he waited to reveal the torture because he was afraid, but Rafeedie strongly indicated at the end of the hearing that his eventual decision would be to allow the doctor to be tried.

Rafeedie said higher courts have "upheld activities much more egregious than this" and that congressional action would be needed to bar U.S. agents from abducting foreigners for trial in the United States.

During his testimony, Garate Bustamante contradicted his earlier account of the abduction as presented in a declaration filed by the government. In their separate declarations, Garate Bustamante and Berrellez said the Mexicans willing to abduct the doctor were told beforehand that they would receive the $50,000 reward and expenses.

Garate Bustamante insisted today that the reward and expense offer was made only to Mexican officials who had negotiated for the exchange of fugitives. The doctor's Mexican abductors, Garate Bustamante said, "did it more for friendship than for money" and were not promised a reward.

Berrellez said he and other DEA officials met with Jorge Castillo del Rey, a commander of the Mexican Federal Judicial Police, in Los Angeles in December to discuss the fugitive exchange.

He said the Mexican attorney general wanted the arrangement kept secret because "if Mexican citizens found out that they were violating their own laws, the Mexican people would be very upset and it would be a big embarrassment to the Mexican attorney general."

The Mexican attorney general's office said tonight it will ask the United States to extradite Berrellez and Garate Bustamante and ordered Mexican authorities to issue arrest warrants for both men as the "intellectual authors" of the kidnapping.

A communique issued by the office of Attorney General Enrique Alvarez del Castillo denied a testimony by Berrellez that Alvarez del Castillo had known of the U.S. plan to kidnap Alvarez Machain.