Don Whittington charged up to a desk inside a gargantuan Fort Lauderdale warehouse built from blue corrugated metal. He was seething. "You're a bitch," he hissed at the receptionist.

Then, the five-foot-11 Whittington, who was once a championship racecar driver before earning an 18-month federal prison sentence for involvement with drug smuggling, turned to an African-American man standing nearby. "You're a fucking nigger," he snorted.

Later, according to a lawsuit filed in Broward County Circuit Court, he "spat on" several employees of a company he was trying to evict for nonpayment of rent. "I'm going to fix you so good that you don't even know it," he allegedly shouted.

That 2011 incident hints at the volatile, mysterious world of Don Whittington and his brother, Bill. Today the pair is starring in an only-in-South Florida tale of intrigue, crime, and the CIA that arcs from the Indy 500 to Guantánamo Bay, with a cameo by Latin television star María Celeste Arrarás.

Though not long ago it seemed as if the Whittingtons' outlaw days were behind them, this past November, the Miami office of the Drug Enforcement Administration filed a damning search warrant application accusing the Whittingtons of helming an international ring that sells planes at inflated costs to drug smugglers in Mexico, Venezuela, Colombia, and Congo. Over the past decade, the filing asserts, Bill Whittington's account with LGT Bank in Vaduz, Liechtenstein — "a preferred financial location for narcotics traffickers" — has grown from $1 million to nearly $11 million.

The Whittingtons, who allegedly operate the scheme out of a mammoth hangar called World Jet on Cypress Creek Road in Fort Lauderdale, don't want to talk. Reached for comment at his $2 million Fort Lauderdale estate on San Marco Drive, Don Whittington asked, "What's this about?" and then hung up. His son Donnie, a broad-shouldered, auburn-haired 26-year-old, said, "I'm not going to say anything about anything," while escorting a reporter out of World Jet headquarters. "It's an awkward subject."

But Don and Bill Whittington, who graduated from Fort Lauderdale's Stranahan High School in the 1960s, haven't always been so shy. In the 1980s, when the brothers had shaggy hair and boxers' braggadocio, their names flooded local media. In 1979, they won the prestigious 24 Hours of Le Mans, one of the world's oldest races, which traverses the French countryside.

They each participated in five Indy 500 races, and Don finished sixth in 1982. In those days, the brothers styled themselves as daredevils. "It's easy to go back out after [a crash]," Bill told the Miami Herald in 1983. "There isn't any college you can go to for this. Just the school of hard knocks."

That predilection for risk-taking soon manifested off the asphalt. While they won accolades for racing, the brothers were stewarding a worldwide marijuana-smuggling operation. In March 1986, they were charged with defrauding the U.S. government of $20 million in taxes derived from that network. Even the $203,000 racecar they'd used to win the 24 Hours of Le Mans had been the product of drug money. The feds accused Bill of trafficking "multi-ton quantities of marijuana" into the country and "disguising the narcotic profit by investing into legitimate business ventures." Don was charged with tax evasion.

The men pleaded guilty and agreed to forfeit $7 million. Don got 18 months in federal prison. His brother was hit with 15 years.

Bill was released early from prison, in 1990. With Don, he later founded World Jet, a successful company that hails itself on its website as one of the largest private, full-service hangars in South Florida.

But whispers hounded the brothers. Who, precisely, were the Whittingtons? And where was this pair of disgraced racecar drivers getting their new millions?

Then, on September 24, 2007, a turbo jet laden with nearly four tons of cocaine crashed in the Yucatán. Flight logs reportedly showed the plane had flown years earlier from Washington, D.C., to Guantánamo. That revelation incited speculation that, in addition to smuggling drugs, the plane had also been used in the rendition of suspected terrorists.

The aircraft's owner was a shell company called Donna Blue. According to the recent Miami DEA affidavit targeting the Whittington brothers, the firm was being used for "Operation Mayan Jaguar," a clandestine program run by U.S. Immigration and Customs Enforcement. The Whittingtons, the affidavit alleges, were "implicated" in selling the turbo jet to the undercover operation.

One of the jet's pilots was Gregory Dean Smith, a Fort Lauderdale man who today is a "target for trafficking cocaine from South America to Central America," the Miami DEA affidavit alleges. Stranger still, the investigative website Narco News alleges Smith, who today pilots for the Whittingtons, has worked for numerous U.S. intelligence operations.

Around the same time, the Austrian Parliament claimed two planes owned by the Whittingtons had stopped at Guantánamo Bay likely on missions for the CIA, according to Austrian government documents. The planes were listed by their tail numbers, N229WJ and N252WJ. The documents raise the possibility that the CIA employed the Whittingtons in the War on Terror despite the brothers' well-known rap sheets for trafficking — and at a time when the DEA now says the two were back in the drug business.

In early 2010, Don Whittington allegedly agreed to transport infamous Cuban terrorist and ex-CIA agent Luis Posada Carriles to a court appearance, but the flight was canceled. (Whittington denied that allegation but couldn't explain why court documents listed his plane as the terrorist's ride.)

Whatever their involvement with the intelligence underworld, the Whittingtons have clearly been successful businessmen. Bill won a $250 million bid in 2008 in Pagosa Springs, Colorado, to construct an opulent spa and resort managed by his daughters. Those who know the Whittingtons say their success draws from a nearly obsessive attention to detail. "Don Whittington wants things done correctly," pilot Greg Smith recalls. "He's no-nonsense, and he won't take any crap from me or anybody."

Indeed, if the 2011 lawsuit between Don Whittington and Telemundo host María Celeste Arrarás proves anything, it's Whittington's pugnaciousness. The two had a falling-out when Whittington tried to evict Arrarás' company, Infinity Air Services, from World Jet's hangar. Whittington alleged her company had fallen behind on rent, but her organization responded that Whittington had "engaged in a reign of terror."

His "insults and threats included calling one employee who was African-American a 'nigger,'" the lawsuit says. "He vandalized [our] premises by tearing down personal property affixed to the premises, and... insinuating verbally that he would plant drugs on [a] plane. As he was previously convicted for drug smuggling, employees became afraid of being 'framed.'" (The trial court ultimately sided with Whittington in the eviction, but litigation on the alleged verbal abuse continues.)

As the courtroom drama raged, a yearlong Miami DEA investigation into the Whittingtons was sharpening its focus. "It revealed that Don Whittington sold and leased multiple jet aircraft to [drug-trafficking] agents," says the DEA affidavit, filed this past November in federal court in Denver. One of those agents was an alleged Congolese drug trafficker. "According to the DEA confidential source, proceeds from the [Whittington] sales have been invested in a ranch and a spa in western Colorado. Proceeds are laundered through the hotel or spa," the affidavit states.

At 9 a.m. November 25, federal agents swarmed World Jet's Fort Lauderdale hangar and removed passels of paper. But since then, all has been quiet. A DEA spokesperson said the agency is continuing its probe of the Whittingtons, but so far no charges have been filed, no arrests made.

And these days, World Jet continues to operate as normal, behind eight-foot-tall fences studded with barbed wire and against a backdrop of jets taking off for faraway lands.