By MARK STEVENSON Associated Press

MEXICO CITY (AP) — It was surprising when Mexico's most-wanted drug lord landed at an airfield near El Paso, Texas in July. But the story of how he got there is now growing into a scandal that threatens top figures in Mexico's ruling party. It is a complex web involving the alleged abduction of drug lord Ismael "El Mayo" Zambada and the killing of a politician who allegedly lured him to a secret meeting where he was kidnapped and flown to the United States, where he was arrested. The slain politician was a fierce political rival of the governor of Sinaloa state, who has been a sort of point-man for President Andrés Manuel López Obrador's policy of not confronting drug cartels.

MEXICO CITY (AP) — It was strange and surprising when Mexico's most-wanted drug lord landed at an airfield near El Paso, Texas in July, but the story of how he got there is now growing into a scandal that threatens top figures in Mexico's ruling party.

At issue is whether Rubén Rocha — the governor of the cartel-dominated state of Sinaloa and a close ally of the president — may have held meetings with top leaders of the Sinaloa cartel, the main producer of deadly fentanyl that kills 70,000 Americans per year.

The saga involves skullduggery worthy of a 1940s film noir, but it threatens to undermine President Andrés Manuel López Obrador's central assertion that, while he refuses to confront Mexico's drug cartels, he also makes no deals with them.

On Thursday, federal prosecutors said Sinaloa state officials mishandled evidence in an apparent attempt to cover up the July 25 murder of Héctor Cuén, a politician who allegedly helped lure drug lord Ismael "El Mayo" Zambada to a meeting where he expected to find Gov. Rocha. Instead, Zambada was abducted by another drug lord and flown to the United States, where he was arrested.

Zambada said in a letter released by his lawyer that Cuén was murdered at the house where the abduction took place. Gov. Rocha has maintained Cuén was killed by gunmen in a botched robbery at a gasoline station later that day, and he even provided security camera footage of the alleged attack.

But federal prosecutors quickly noted something was wrong: post-mortem records showed Cuén's body had four gunshot wounds, while only one gunshot can be heard on the security camera footage, and gas station employees said they didn't hear any.

And the feds said Sinaloa officials violated all murder investigation rules by allowing Cuén's body to be cremated. Gov. Rocha denies planning any meeting with Zambada, but in the rest of the dispute over the events of that day, the drug lord's version now appears more credible. The Sinaloa state chief prosecutor resigned on Friday.

"It appears that what they did in Sinaloa was, as they do frequently, to cover up the crime," said Mexican security analyst David Saucedo.

López Obrador acknowledged Friday that "there have been contradictions in the case from the very start," and promised to get to the bottom of it. Federal prosecutors have taken over the case and the president said "the Attorney General's Office is showing that there are things that don't add up."

Gov. Rocha has been a sort of point-man for López Obrador's "hugs not bullets" policy of not confronting drug cartels; his state is home to Mexico's most powerful gang.

The governor has accompanied the president on his most controversial trips: the half-dozen visits the president has made to Badiraguato, Sinaloa, the hometown of imprisoned drug lord Joaquin "El Chapo" Guzmán.

At one point, Lopez Obrador even stopped to chat with Guzmán's now-deceased mother. Badiraguato is also where Gov. Rocha was born.

The Mexican president's drug policy is based on a series of unwieldy propositions: it's no use arresting drug lords, because new ones will pop up. López Obrador claims high-profile cartel arrests were a policy forced on Mexico by the United States; refusing to continue them is a victory for national sovereignty.

The president claims Mexican cartels don't manufacture fentanyl (they do, and top officials in Mexico have admitted as much), and that American social problems, not Mexican cartels, are responsible for the fentanyl crisis.

López Obrador says drug cartels are essentially "respectful people" who "respect the citizenry" and mostly just kill each other. The only solution to Mexico's dizzyingly high murder rate, he says, is to use job-training programs to drain the pool of potential drug cartel recruits.

All those assertions rest on one central proposition that now appears in doubt: that while the government doesn't attack cartels, it also doesn't make deals with them. While nobody has presented any credible evidence that the president has met with drug lords, analysts say Gov. Rocha, a member of the president's Morena party, did.

"It isn't a suspicion any more, it's a certainty," said Saucedo. "What has become clear is that what the government has is intermediaries who negotiate with the Sinaloa cartel." Rocha has denied meeting or dealing with drug lords.

Saucedo notes it would not be the first time that Mexican governors or their relatives have met with drug lords — one was caught on video tape doing so in 2014.

Zambada's arrest in late July, along with El Chapo's son, Joaquín Guzmán López, was embarrassing for Mexico from the start, because the Mexican government wasn't even aware of it.

But it was Zambada's later account of how he was duped by the younger Guzmán — who always intended to turn himself in to U.S. authorities and apparently took along Zambada, who had a $15 million bounty on his head, as a prize — that has set Mexico's political establishment trembling.

Zambada has said that Guzmán, who he trusted, had invited him to the meeting to help iron out the fierce political rivalry between Cuén and Gov. Rocha. Zambada was known for eluding capture for decades because of his incredibly tight, loyal and sophisticated personal security apparatus.

The fact that he would knowingly leave that all behind to meet with Gov. Rocha means that Zambada viewed such a meeting as credible and feasible. Ditto the idea that Zambada, as the leader of the oldest wing of the Sinaloa cartel, could act as an arbiter in the state's political disputes.

Gov. Rocha has denied he knew of or attended the meeting where Zambada was abducted. In an odd piece of political theater, Rocha published the flight plan of a plane that he said took him out of the state that day on a family vacation, and even published a video that day carefully explaining that "I am not in the state."

But in the central dispute about what happened that day, Zambada's version appears to be more credible.

"It appears to me that El Mayo Zambada's version is totally more credible," said Saucedo. "It all adds up."