The son of infamous drug lord "El Chapo" has appeared in court for the first time since being extradited to the US from Mexico.
Ovidio Guzman Lopez denied drug and money laundering when he appeared at a Chicago court on Monday - three days after he was brought to the US.
Guzman Lopez, 33, and his three brothers - collectively known as "Los Chapitos" - inherited their father's empire after he was convicted of murder and drug charges in 2019.
The brothers inherited their father's multibillion-dollar empire when he was incarcerated, allegedly steering it into synthetic drugs including methamphetamine and the powerful opioid fentanyl, which has been blamed for killing almost 200 people in the US every day.
Guzman Lopez, known as "The Mouse", and his siblings were all indicted by US prosecutors in April amid claims they produced huge amounts of fentanyl and sold the drug at its lowest price.
They operated a huge international trafficking operation that saw drugs transported to the US via airplane, submarines, fishing boats and rail cars, bringing in hundreds of millions of dollars in profits, it is alleged.
The brothers all deny the allegations and claim they are the "victims of persecution" and "scapegoats".
"We have never produced, manufactured or commercialised fentanyl nor any of its derivatives," they said in a statement.
The extradition of Guzman Lopez is "testament to the significance of the ongoing co-operation between the American and Mexican governments on countering narcotics and other vital challenges," US Homeland Security advisor Liz Sherwood-Randall said.
Guzman Lopez was captured by Mexican security forces in Culiacan, the capital of Sinaloa state, in northwest Mexico, in January.
His arrest sparked a wave of violence leading to the deaths of 30 people, including 10 military personnel, with the Mexican army deploying Black Hawk helicopter gunships in a shoot-out against the cartel's truck-mounted 50-caliber machine guns.
Cartel gunmen hit two military aircraft, forcing them to land.
They also sent gunmen to the city's airport, where both military and civilian aircraft were targeted.
Officials attempted to detain Guzman Lopez in Culiacan in 2019 but were forced to abandon their operation after similar violence unfolded.
Mexico's President Andrez Manuel Lopez Obrador personally ordered his release after hundreds of cartel members overwhelmed security forces.
El Chapo escaped prison in Mexico twice before he was finally arrested and extradited to the US in 2017, ahead of his conviction at a federal court in Brooklyn.
His wife, Emma Coronel Aispuro, was released from US custody last week after serving less than two years behind bars.
The 34-year-old is said to have helped to plan her husband's escape from prison in 2015, which involved digging a tunnel underneath a jail.