A leader of Colombia's defunct Medellin cartel is in a "living hell" of solitary confinement after being extradited to the United States to face cocaine trafficking charges, his attorney said Monday.

Fabio Ochoa Vasquez, the highest-profile Colombian sent to face U.S. justice since 1987, pleaded innocent at his first U.S. court appearance to charges that he helped smuggle 30 tons of cocaine a month and spirited away the profits.

"It is very difficult for Fabio to be where he is," defense attorney Jose Quinon said, describing 23 hours a day of lockdown and relatives lacking visas to visit him. "For him it is a living hell to be here to await trial."

Ochoa, 45, who was flown to Miami over the weekend, agreed to be held without bond on the condition that the question could be raised again later.

He has immunity on crimes committed before a new extradition treaty was signed in 1997 but could face a life sentence if convicted of three conspiracy counts charging he helped smuggle tons of cocaine after 1997.

Ochoa has acknowledged drug trafficking "in the distant past," Quinon said. But his attorney said Ochoa "categorically denies" any subsequent crimes covered by the extradition treaty.

Quinon was co-counsel for Carlos Lehder Rivas, the last major cartel figure to be sent north by Colombia in 1987. Lehder was convicted after a long trial in Jacksonville and began cooperating with investigators after getting a life sentence.

The Ochoa extradition prompted a State Department warning to Americans in Colombia to take extra security precautions. A bombing blamed on Colombia's extradition policy killed eight people in Bogota in 1999.

Three men extradited by Colombia under the same 43-defendant indictment also appeared in court with Ochoa. They are: Jairo Sanchez Christancho, who also pleaded innocent, Jario de Jesus Mesa Sanin and Luis Fernando Rebellon Arcila. Bond hearings were set for them over the next two weeks.

The Fort Lauderdale indictment issued in 1999 has been expanded with new defendants, including Ochoa, four times since then to cover a two-year conspiracy to move cocaine from Colombia through the Bahamas and Mexico to the United States.

The charges themselves are a bare-bones recitation of anti-drug statutes that make anyone convicted subject to a life sentence. By treaty, no extradited Colombians can face the U.S. death penalty.

Ochoa's sister, Martha Nieves Ochoa, claims the DEA concocted the charges in retaliation for his refusal to work undercover following his release from a Bogota prison in 1996.

Ochoa and his two older brothers were at the top of the Medellin cartel with the late Pablo Escobar when organizers took a fragmented business and applied a corporate approach to cocaine smuggling in the 1970s and 1980s.

In 1991, Ochoa was the first major trafficker to surrender to the Colombian government in return for a promise that he would not be extradited.

But U.S. prosecutors say Ochoa got back into the cocaine trade after going free in 1996. He was arrested in 1999 along with dozens of other suspected traffickers in a joint DEA-Colombian police operation.

Court security was expected unusually tight for Ochoa. The four co-defendants were given their own hearing separate, and Ochoa was escorted through an entrance normally reserved for the judge. At least 15 marshals stood guard during the 10-minute hearing.

Ochoa listened to a Spanish translation through headphones. The hearing was delayed when audio feedback from a TV truck outside filled the courtroom's audio system.

Ochoa is being held in a modern, high-rise jail with slits for windows across from the courthouse and linked to it by tunnel. Walk-hobbling leg chains stay on inmates their entire time outside the jail, and handcuffs are removed in court only to move from a jury box to a podium and back again.