Lawyers for Mexican drugs kingpin Joaquin "Shorty" Guzman on Monday filed an injunction to block any move to extradite him to the United States after he was captured and charged with drugs and arms trafficking, an official said.
Guzman, Mexico's most wanted criminal and boss of the feared Sinaloa Cartel, was caught in the northwest of the country with help from U.S. agents in a pre-dawn raid on Saturday.
The dramatic capture ended his reign as one of the world's most notorious organized crime bosses, and was a major victory for the Mexican government in a long, brutal war.
According to a Mexican justice official, Guzman's lawyers filed the injunction on Monday after the spokesman for a U.S. federal prosecutor said he planned to seek the capo's extradition to face trial in the United States.
However, it is still unclear whether that will happen, and extradition proceedings can take years to complete.
Earlier on Monday, a U.S. Justice Department spokesman said an extradition decision would "be the subject of further discussion between the United States and Mexico". U.S. officials said that President Barack Obama's administration wanted to avoid looking like it was putting pressure on Mexico to move quickly on an extradition.
Mexico has not yet said whether it is ready to do so.
"The security cabinet will need to meet and take the most appropriate decision," Interior Minister Miguel Angel Osorio Chong told a radio station on Monday.
Sensitivities over the issue could mean Guzman is more likely to face justice first in Mexico, where he still has an outstanding term to finish after he broke out of prison in 2001.
Fears of a repeat escape might encourage Mexico's government to hand Guzman over to the United States, but it would also be a tacit admission of ongoing weakness in the justice system. Crime bosses have served terms first in one country, then the other.
While Guzman has been charged with an array of crimes in Mexico, murder is not among them, government and justice officials said. That is despite accusations by security officials that his cartel was behind thousands of killings.