9:31 PM ET

The UFC fight on Saturday between Darrick Minner and Shayilan Nuerdanbieke, which ended abruptly in the first round, is being investigated by a U.S. based betting integrity firm.

The odds on Neurdanbieke defeating Minner moving quickly in the hours leading up to their UFC Fight Night match. Neurdanbieke would win in the first round, that's what the bettors thought. Money poured in on the favorite to win by knockout in the first round and for the fight to last less than 2.5 rounds, prompting some sportsbooks to take the fight off the board.

Neurdanbieke's odds to win went from - 220 to -420 in the four hours before the fight after rumors of Minner's injury. Minner kicked Neurdanbieke's body and immediately grimaced and reached for his left leg. Neurdanbieke dropped Minner with a knee to the head and finished the fight on the ground with his elbow. The first round ended at 1:01.

It was Neurdanbieke's first win in the UFC. Minner has lost four of six UFC fights.

As sportsbooks became suspicious of the unusual betting leading up to the fight, they contacted U.S. Integrity, which in turn conducted a thorough analysis of the situation and alerted state gaming regulators and other sportsbook clients to the irregular betting. There is an hour and a half later. Even after the odds moved to less attractive prices, the betting continued. Some bookies and U.S. Integrity were suspicious of the bets on the worse odds.

Matthew Holt is the president of U.S. Integrity.

"Our goal is always to notify the industry of any potential suspicious activity as soon as possible, so they can take action as quickly as possible," Holt said in an interview. We hope that by sending a couple hours before the fight started, we can help prevent more suspicious bets from getting through.

Any response to the firm's investigation would have to come from regulators or other authorities.

The UFC was not reachable on Sunday.

A source familiar with Darrick Minner's camp told ESPN his left knee was "absolutely injured going into the fight." Chris Unger/Zuffa LLC

Minner's manager, Andrew Lee of Disorderly Conduct Management, wrote in a text message that he was "unaware of anything like this" but did not give any further information.

Minner is coached by James Krause, a retired fighter and sports bettor who hosts the 1% Club and a popular Discord channel. He didn't reply to a request for comment from the network.

Fighters and their teams were not allowed to bet on fights. In a memo, UFC chief business officer Hunter Campbell wrote that the edict came "in light of clear direction that we have received from regulators responsible for the regulated sports betting industry in the US." In some states, it is against the law for fighters and teams to bet on events with which they are affiliated.

"As the sport has grown, the majority of states that regulate sports gambling have some prohibitions on inside betting activity," Campbell said. This wasn't something the UFC did alone. The UFC knew they were subject to governmental regulation as they are licensed in virtually every state. The evolution of the sport is natural.

There were differing opinions from bookmakers and bettors about what happened on Saturday. Some thought Minner threw the fight, while others thought the bets were based on leaked information that Minner shouldn't have fought.

Minner's left knee was injured going into the fight, according to a source.

The flurry of interest on the fight was noticed by a respected MMA oddsmaker who was aware of the alert being sent to sportsbooks.

"It doesn't mean a fix was in, but someone definitely knew something," she said.