From Robert K at Betwwx.com:

There have been many prominent cases of former athletes betting on their chosen sport. MMA is no different. Tito Ortiz is among a long list of fighters that admitted to betting on MMA fights. While there are no official figures we can only assume that the percentage of fighters betting MMA is very substantial. The UFC policy on fighters wagering on MMA seems unclear. Are fighters allowed to bet on themselves or on other fighters and what about their family and friends? Fighters, trainers, managers, promoters, even family appear to be free to bet on MMA fights in Vegas and offshore at online sports books.

We talked to the people who know the real extent of the problem. The guys that take the bets.

"If there were professionals betting on themselves they'd likely get someone to place the wager for them in Las Vegas (rather than bet online). Tito Ortiz has mentioned before that he has personally placed wagers before in Las Vegas. He's very open to where he put his money. MMA fighters can do as they wish as long as they don't bet on themselves under contract or do it illegally like Din Thomas or Kimbo Slice where they fought in people's back yards (unsanctioned fights)," said one online sportsbook representative.

It's a major issue the UFC or any other professional organization is not willing to address. Client lists for any sports book are strictly confidential.

"We'd never be able to divulge any client information to anyone under any circumstances. So for the record we do not have any professional fighters placing wagers with us."

Though there have been a few cases of retired bookmakers exposing former athletes. In his book Bets, Drugs and Rock & Roll former bookie Steve Budin estimates 20 to 25 active NFL players bet on the sport. That would amount to a total of around 3% of NFL roster. Famously, Jaromir Jagr, then a Pittsburgh Penguins star, racked up a US $450,000 debt to Belize-based bookmaker Carib Sports.

With the sport still being in its infancy even those who make it to the UFC may not necessarily earn a living from the sport, making them especially susceptible to inducements.

Then there's the last fight scenario. It's simple economics: for fighters on their last contracted fight or perhaps on the last fight of their career, "taking a dive" becomes awfully lucrative.

In reality, betting on fights is a almost an untraceable activity. It can only be detected with a coordinated effort between police, bookmakers and sporting organizations according to all offshore representative we have spoken to. Europe is at the forefront of the issue. Bookmakers are largely regulated and work side by side with sports authorities. Irregular betting activity is often picked up and followed up with lengthy investigations by individual sports books . If a crime is detected law enforcement is also notified.

The Fertittas seem open to a more regulated system and are known as gambling advocates, however only if it's limited to Las Vegas.

"If people want to bet legally on the UFC, we think that it's not a bad thing," said Lorenzo Fertitta last year. The Ferrittas themselves, who own Stations casino, choose not to accept bets on UFC fight in order to avoid a potential conflict of interest. The Fertitta support the Vegas monopoly of sports betting and consider all offshore wagering to be illegal.