LOS ANGELES -- A federal judge who had found that a doctor suspected in the torture-death of Drug Enforcement Administration agent Enrique "Kiki" Camarena had been illegally brought here for trial yesterday denied bail after an appellate court stayed the judge's order that the doctor be returned to Mexico.

Camarena and his pilot, Alfredo Zavala Avelar, were tortured and killed in Guadalajara, Mexico, in 1985. Nearly 50 people have been arrested in connection with the case in Mexico and the United States and several have been convicted.

Humberto Alvarez Machain, a gynecologist, was charged with violent crimes in aid of racketeering, conspiracy, kidnapping and murder. Prosecutors said he administered drugs to keep Camarena alive while he was being tortured prior to death. He could be sentenced to life in prison if convicted.

Alvarez Machain was brought to the United States on April 2 to face charges, but U.S. District Judge Edward Rafeedie ruled Aug. 10 that Alvarez Machain had been kidnapped illegally and should be returned to Mexico. On Thursday, the 9th U.S. Circuit Court of Appeals stayed Rafeedie's order, making Alvarez Machain eligible for a bail hearing. Rafeedie denied bail on the grounds that Alvarez Machain was a "flight risk."