Rafael Caro Quintero, the one-time head of the Guadalajara drug cartel in Mexico, who is wanted in the 1985 kidnapping and murder of a Drug Enforcement Special Agent Enrique Camarena “Kiki” Salazar has been added to the Federal Bureau of Investigations most wanted fugitives.

The FBI, the Drug Enforcement Administration, the U.S. Marshals Service and the Department of State “are committed to bring to justice this dangerous criminal and cartel leader responsible for the brutal murder” of Camarena, said FBI Deputy Director David L. Bowdich. The State Department has offered a reward of up to $20 million for information leading to his arrest.

Authorities arrested Caro Quintero in Costa Rica in 1985 for Camarena’s torture and murder and extradited him to Mexico. After he was sentenced in 1989 to 40 years in prison, the Mexican government confiscated his wealth. His holdings at the time included a property owned by an offshore company set up by Mossack Fonseca, the now defunct Panama law firm whose files were the basis of the International Consortium of Investigative Journalist Panama Papers investigation.

The property was handed over to Costa Rica’s government, which then passed it to Costa Rica’s National Olympic Committee.

The files show that in March 2005, Costa Rican Olympic officials asked Mossack Fonseca to help them obtain clear title to the property.

A lawyer working for Mossack Fonseca told the Costa Rican visitors that the offshore company’s shareholders would have to decide. A document in Caro Quintero’s company files labeled “Case details > shareholders” contained only a notation: “No data found!” But the lawyer wrote in an internal email exchange that it “appears the real owner of the estate, and therefore of the company, was the narco-trafficker Rafael Caro Quintero.”

An email from Jurgen Mossack. “Compared to Quintero even Pablo Escobar was a baby!”

Jurgen Mossack, a co-founder of the law firm and one of three directors listed for the company, wasn’t interested in getting on Caro Quintero’s bad side.

“Compared to Quintero even Pablo Escobar was a baby!” he wrote in an email exchange, referring to the notorious Colombian drug lord. The upshot was that Mossack Fonseca would resign from its representation of Caro Quintero’s offshore company. “I don’t want to be among those Quintero visits after jail.”

In 2013, Caro Quintero was released from prison on a technicality and immediately disappeared.

Quintero was added to the FBI most wanted fugitives list on April 12.