SAN DIEGO -- The oldest of four brothers in the alleged Arellano-Felix drug cartel pleaded not guilty Monday to a pair of 26-year-old drug charges.

Francisco Rafael Arellano-Felix, 56, was extradited from Mexico to San Diego on Saturday. He appeared at his arraignment before Magistrate Judge Anthony Battaglia dressed in a green jumpsuit and blue deck shoes.

The bespectacled defendant denied charges of conspiracy to possess a controlled substance with intent to distribute and possession of a controlled substance with intent to distribute.

Assistant U.S. Attorney Laura Duffy told the judge that the government would be seeking to detain Arellano-Felix without bail pending the resolution of his case because he was considered a flight risk.

Battaglia set a detention hearing for Thursday afternoon and a motion hearing for Sept. 25 before U.S. District Judge Irma Gonzalez.

Arellano-Felix was extradited to San Diego over the weekend from a prison in Mexico City, where he spent the past 13 years, Duffy said.

She said U.S. prosecutors were pleased that the Mexican government decided to send the defendant to the United States to face charges that he sold 9 ounces of cocaine to an undercover agent at a Midway Drive hotel 26 years ago.

"We're serious about prosecuting drug offenses," the prosecutor said outside court.

Arellano-Felix -- who posted bail and fled to Mexico 26 years ago -- faces a maximum of 30 years in prison if convicted of both drug charges, Duffy told reporters.

U.S. authorities said the defendant did not play a major role in running the Arellano-Felix cartel. He was arrested in Tijuana in 1993.

His younger brother, Javier Arellano-Felix, was captured on a fishing boat off the coast of Cabo San Lucas in August and was brought to San Diego to face federal charges.

Javier Arellano-Felix and 11 other alleged high-ranking members of the cartel were indicted in federal court in San Diego in July 2003 on charges of importing and distributing drugs into the United States.

Javier Arellano-Felix and his brothers, Benjamin and Eduardo, were charged in December 2003 with conducting an illegal enterprise through a pattern of racketeering activity, conspiring to import and distribute cocaine and marijuana, and money laundering.

Another brother, Ramon Arellano-Felix, considered the cartel's enforcer, was killed in a shootout with police in 2002. Benjamin Arellano-Felix was arrested a few weeks later.

Eduardo Arellano-Felix is still at large.

Authorities say Francisco Javier Arellano-Felix took over the Tijuana cartel in 2002. The Arellano-Felix family has controlled the Mexican drug trade since the late 1980s, authorities said.

The indictment also alleges that the Arellano-Felix Organization negotiated with Colombian cocaine traffickers to buy tons of cocaine, and then arranged to have it smuggled into the United States.

The Arellano-Felix Organization recruited bodyguards and assassins who killed rival drug traffickers, informants and Mexican law enforcement and military personnel, as well as members of the news media, the government alleges.

The indictment accuses the Arellano-Felix organization of carrying out 20 murders in the United States and Mexico.