Federal court documents reveal a member of the Sinaloa cartel accused the U.S. Drug Enforcement Agency (DEA) of entering into a secret deal to obtain information about rival cartels.

Jesus Vincente Zambada-Niebla, the son of cartel leader Ismael Zambada-Garcia, was charged in an indictment involving conspiracy to import and distribute cocaine and heroin. Zambada-Niebla claimed, “…the cartel would supply information about rival cartel leaders and their associates to the Government in return for carte blanche for the Sinaloa Cartel to continue their narcotics trafficking business in the United States and Mexico without interference."

Criminal defense attorney and former federal prosecutor John Kirby told NBC 7, “In my experience, it has happened where the agent develops a relationship with someone and says, ‘Okay don't worry you're not going to be prosecuted.’”

Kirby says DEA agents have informants who are members of drug cartels, but he does not believe the DEA or the U.S. government would offer full immunity to the entire cartel.

“It's to some extent unthinkable the DEA would say, okay Sinaloa cartel you can move all the drugs you want and we're not going to arrest anyone as long as you give us information on a rival gang. That's just not going to happen,” Kirby said.

NBC 7 reached out to the DEA and received this response:

Law enforcement meets with potential informants regarding building drug investigations. The idea we are able to offer immunity or permission to continue drug trafficking is simply not true.

Court documents obtained by NBC 7 also revealed "...the only support offered by Zambada to shore up these allegations is a declaration by Fernando X. Gaxiola...Gaxiola is an attorney who represents Zambada."

The documents go on to show government officials admitted there was an agreement, but said it did not involve promises of immunity. The judge in the case denied Zambada's request to dismiss his indictment.