Even as outgoing President Felipe Calderon began the process of turning over his office to his successor with a midnight ceremony in Mexico City’s massive National Palace, his administration was working into the wee hours to hand a jackpot to two of Mexico’s most controversial casino operators.

As Calderon presented incoming President Enrique Pena Nieto with a green-white-and-red Mexican flag, regulators a few blocks away approved a slew of new permits, acting first at 11:58 p.m. on Nov. 30 – ka-ching! – and again at 3:16 a.m. Dec. 1 – ka-ching! In all, the two operators won permits for 94 new gaming establishments. Calderon’s term officially ended at 10 a.m. Dec. 1.

The action redefined the contours of the gaming industry in Mexico and is likely go down in history as a stain on 12 years of rule by the National Action Party, which promise to end 71 years of corrupt rule by the Institutional Revolutionary Party. That pledge, however, foundered on the PAN’s messy relationship with dozens of illegal gaming halls that were created during its reign.

Calderon’s predecessor, fellow PAN member Vicente Fox, oversaw a government that reopened the doors to the gaming industry and, in an echo of history, issued hundreds of casino permits in its final months.

The legality of the Calderon government’s last-minute giveaway of casino permits has been challenged by a judge in the northern Mexican state of Nuevo Leon, who ordered them annulled.

But the permits are only one element of an unfolding scandal that is centered in the gaming and lotteries bureau of the Interior Secretariat, Mexico’s most powerful ministry.

Darkening the clouds over the casino regulators are allegations from a 46-year-old corporate lawyer who was once married to a senior Interior Secretariat official. Among her allegations is that she witnessed Calderon’s personal secretary, Roberto Gil Zuarth, accept a backpack with $800,000 to help smooth over opposition to opening a casino in Queretaro, a prosperous city north of the capital.

Talia Vazquez Alatorre also claims she was a victim of a brutal gang rape led by her then-husband, who is now in prison.

In her crusade for vengeance, she has spilled endless details of the allegedly crooked inner workings of the gaming and lotteries bureau. Seated in an airy office in southern Mexico City, she broke down several times over two lengthy interviews in which she detailed how her ex-husband and two other key former Interior officials left government and dove into the gaming business, falsifying backdated documents with official seals in order to commandeer rival casinos as well as to operate casinos of their own.

Gil Zuarth, who is now a senator and head of the PAN faction in the upper chamber, reacted angrily, saying he would file a defamation suit against Vazquez.

“I have never seen her, I’ve never been to her house . . . nor much less received money from these people or those linked to them,” Gil Zuarth told Mexico City’s MVS Radio on Jan. 9.

Calderon, who this month began a yearlong fellowship at Harvard’s John F. Kennedy School of Government, could not be reached for comment through the university

Casinos operate in a murky legal environment in Mexico. A 1947 law bans gambling. Fox, who came to office in 2000, vowed – and failed – to overturn the ban. Instead, he issued rules that allowed sports betting and bingo parlors. Pushing the rules further, casinos popped up with electronic poker and blackjack machines, and even roulette, and poker and blackjack tables with dealers.

When Calderon came to office in 2006, he pledged not to issue casino permits until order was restored. But Interior Secretariat and gaming and lotteries bureau officials devised schemes for those who sought a workaround to open casinos.

One scheme functioned like this: Instead of simply ignoring requests for permits, gaming bureaucrats would issue documents graced with official seals stating that applicants had fulfilled requirements to open casinos but would not be granted permits. Those soliciting the permits would then appeal to friendly judges that their rights had been infringed by arbitrary action, earning amparos, or judicial writs, which protected them as they built their desired casinos.

Under another scheme, off-the-books casinos would begin paying federal taxes, building a legal framework around the illicit origins of the gaming halls.

Such strategies led to dozens of either illegal or gray-area casinos. In 2009, a legislator of the leftist Party of the Democratic Revolution, Jesus Zambrano, handed the then-Interior secretary a list of 46 illegal casinos that operated “across the country at the pleasure of the Secretariat.”

Allegedly behind some of the schemes was Juan Ivan Pena Neder, a Chihuahua lawyer who in 2007 won a powerful post as coordinator within the sprawling Interior Secretariat. In the key position, Pena Neder oversaw the head of the gaming and lotteries bureau, Roberto Correa Mendez.

Pena Neder remained in the job only five months. After leaving, he joined with Correa and a third senior Interior official, both of whom also left their Secretariat jobs, to enter the casino business.

Shortly afterward, Pena Neder married Vazquez, the corporate lawyer, who said she was swept away by his savvy.

“He’s a man with a very high IQ,” she said. “Juan Ivan could convince the devil himself of what he wants.”

The two formed a joint law firm but the marriage lasted only a year and a half. Pena Neder now resides in a federal prison in Matamoros, along the border with Texas, awaiting trial on charges he and two associates raped his wife at gunpoint in March 2011.

“He had a gun to my head,” Vazquez said. “I was bleeding all over.”

Vazquez filed criminal charges, drew up divorce papers and prepared sworn statements that she took to the Attorney General’s Office and the Interior Secretariat, demanding a probe into “likely illicit activity” in the gaming and lotteries bureau.

One statement listed 29 casinos that Vazquez asserted were operating without proper licenses and local permits, three of them owned by her husband and his associates.

Vazquez said high-level officials snorted at her assertions. Only a gruesome tragedy kept her campaign alive. On Aug. 25, 2011, gangsters firebombed a casino in Monterrey, an industrial city near the border with Texas, as gamblers played slots. By the end of the day, 52 bodies were counted. The casino owner fled to Miami.

Pena Neder, it turned out, was a legal adviser to Casino Royale, the firebombed upscale gaming hall, and his name surged into the news.

Before Vazquez’s marriage came apart, she said she learned that her husband had letterheads from the Interior Secretariat and official seals that allowed him to falsify rulings from the gaming bureau and sell them to clients.

She said Pena Neder and his associates had confederates within the bureau who did their bidding in exchange for payoffs.

Two companies found particular favor at the bureau. Both operated casinos for Entretenimiento de Mexico, a permit holder based in Monterrey that operates 24 casinos. By 2011, Entretenimiento decided to break with the two operators.

“In 2010, they stopped paying us,” said Eduardo A. Campos Semeno, Entretenimiento’s spokesman.

A year later, the Monterrey company informed the gaming bureau that it had severed relations with both operators, meaning that they had no legal license to operate casinos.

“We’ve informed Interior at least five times that these companies are no longer with us,” Campos said. After months passed with no action, we thought to ourselves, ‘They are protecting these guys,’” Campos said.

The two companies – Producciones Moviles S.A. and Exciting Games – are the ones who hit the jackpot with the issuance of new permits on Nov. 30 and Dec. 1, even though current or former principals from both firms face criminal charges.

The chairman of the board of Producciones Moviles, Lino Armando Vazquez Mata, was arrested in September 2011 on organized crime and drug trafficking charges. Producciones Moviles says he’s been removed him from any role in the company.

The man identified as a principal shareholder in Exciting Games, Alfredo Moreno Quijano, was ordered arrested in October for fraud, the details of which have not been made public.

Televisa, the Mexican conglomerate that is the world’s largest Spanish-language broadcaster, has given intense coverage to the current scandal shaking the casino industry – without reminding viewers that it has a vested interest. Televisa operates casinos under the Play City name, holding permits to run 130 gaming halls.

A reporter for Televisa interviewed Pena Neder this week in the Matamoros prison where he is held. He denied his ex-wife’s allegations, saying they were “absolutely without grounds, ridiculous.” He added that he’d been working for “a sheikh from Dubai” before his arrest.

Some analysts assert that different PAN factions earn payoffs from different casino groups, leading to frictions.

“The PANistas discovered that a gold mine existed behind the permits for lotteries, bingos, horse racing and, above all, casinos. One could do good business protected by the permits without taking public monies and sinning,” Ramon Alberto Garza, editor of Reporte Indigo, wrote this week.

The racket made the Interior Secretariat crucial for organizing the corruption – but also a palace of intrigues and misfortune.

Under Calderon, two Interior secretaries died in air crashes. Juan Camilo Mourino, who helped engineer Calderon’s 2006 election, perished when his Learjet plunged into an upscale Mexico City neighborhood Nov. 4, 2008. Three years later, another secretary, Jose Francisco Blake Mora, was killed in a helicopter crash to the south of the capital.

Another former Interior secretary under Calderon, Fernando Gomez-Montt, is principal in a law firm with close ties to casino operators.

The scandal has boomeranged back to Calderon in another way.

His older sister, Luisa Maria Calderon, is now a PAN senator from the family’s home state of Michoacan. Her alternate – who would take her place in Congress if she were she unable to serve – is Lizette Clavell, a close friend of Pena Neder’s and a frequent visitor to the prison where he is housed.

The senator said she barely knows her alternate, an assertion that drew a scoff from one casino industry official, who said it underscored how casino money penetrated politics.

“This is just incredible,” said Campos, the spokesman for the Monterrey casino company. “Given Mexican politics, this is absurd.”

As for the 11th hour giveaway of permits around Dec. 1, Campos calls it “clearly criminal conduct.”

“These actions are not taken by a third-level bureaucrat,” he said.