Four sons of former Mexican drug lord Joaquin “El Chapo” Guzmán have denied in a rare public letter the charge by US authorities that they are major fentanyl traffickers, that they have flooded the US market with the highly potent synthetic opioid, blamed for dozens thousands of American deaths each year.

Last month, the US Department of Justice prosecuted leading figures of the Sinaloa cartel for trafficking fentanyl and other substances, including the children of “El Chapo”, the former leader of this gang, who is currently serving a life sentence in the US.

The letter was sent on behalf of the four sons of the former mastermind, known as “Tsapitos”, among them Ovidio Guzman, who was arrested in January and is expected to be extradited to the US.

“We have never proceeded with the production or commercialization of fentanyl or its derivatives,” the letter, which was uploaded to the Milenio newspaper’s website, states.

The letter was sent to Milenio by the lawyer Jose Refujio Rodríguez. When contacted by the Reuters news agency, Mr. Rodriguez, the criminologist confirmed that the Guzmán family was his client.

In their letter, the sons say they are not leaders of the Sinaloa cartel. They claim to be the victims of a disinformation campaign by politicians, the media and others, portraying them as notorious criminals.

The letter is apparently a reaction to the April 14 press conference in Washington, during which US officials emphasized that the Sinaloa cartel is the main supplier of fentanyl traded on the US market and made special reference to the “Tsapitos”, calling key gang figures, blaming them for the opioid epidemic.

Mexico and the U.S. agreed last month to step up efforts to combat the trafficking of fentanyl, a drug 50 times stronger than heroin, which is blamed for 70,000 of the 106,000 American deaths from opioid overdoses in 2022.