Ismael “El Mayo” Zambada, the powerful long-time leader of Mexico’s Sinaloa cartel, has pleaded not guilty on a 17-count indictment accusing him of narcotics trafficking and murder.

Appearing in a New York court, Zambada did not speak except to give brief answers to a judge through a Spanish-language interpreter.

His lawyers entered the not-guilty plea on his behalf and he sat quietly as he listened to the interpreter.

Leaving court, he appeared to accept some assistance getting out of a chair and then walked out slowly but unaided.

Sought by American law enforcement for more than two decades, Zambada has been in US custody since July 25, when he landed in a private plane at an airport outside El Paso in the company of another fugitive cartel leader, Joaquin Guzman Lopez, according to federal authorities.

Zambada later said in a letter that he was forcibly kidnapped in Mexico and brought to the US by Guzman Lopez, the son of the imprisoned Sinaloa co-founder Joaquin “El Chapo” Guzman.

US Magistrate Judge James Cho ordered Zambada to be detained until trial. His lawyers did not ask for bail and prosecutors in Brooklyn had asked the judge to detain him.

In a letter to the judge, prosecutors called Zambada “one of the world’s most notorious and dangerous drug traffickers”.

“The defendant maintained an arsenal of military-grade weapons to protect his person, his drugs, and his empire,” they wrote.

“His heavily armed private security forces were used as his personal bodyguards and as protection for drug shipments throughout Mexico, Colombia, Ecuador and beyond.

“Moreover, he maintained a stable of ‘sicarios’, or hitmen, who carried out gruesome assassinations and kidnappings aimed at maintaining discipline within his organisation, protecting against challenges from rivals and silencing those who would co-operate with law enforcement.”

That included ordering the murder, just months ago, of his own nephew, the prosecutors said.

Zambada pleaded not guilty to the charges at an earlier court appearance in Texas.