An Edmonton MMA fighter who was left in critical condition after being knocked out during a boxing match on Friday has died, his family has confirmed.

"It is with incredible sadness, sorrow and heartbreak to report that Tim has passed away today," Tim Hague's sister, Jackie Neil said in a statement Sunday.

"He was surrounded by family, listening to his favourite songs. We will miss him so greatly."

Hague, 34, was taken to hospital in critical condition after being knocked out by Adam Braidwood in a fight at the Shaw Conference Centre on Friday. In a video from the match, Braidwood is seen knocking Hague down multiple times.

Hague, who fought out of Edmonton, also fought in the UFC. His nickname was "The Thrashing Machine."

The Edmonton Combative Sports Commission, which regulates professional combative sporting events in the city, issued a statement Sunday afternoon.

Executive director Pat Reid said a post-fight review is completed immediately after each fight. But he said following the news of Hague's condition after Friday's match, the commission has extended its request for reports to all referees, ringside judges, physicians, chief inspector, paymaster and the presiding inspectors assigned to the bout.

Reid said the commission will determine the next steps after evaluating those reports. "Our thoughts and prayers are with Tim and his family," Reid said at the conclusion of the statement.

A heavyweight trained in jiu-jitsu, Hague put his teaching career on hold to make his pro MMA debut in 2006. Hague compiled a 21-13 MMA record before he was cut from the UFC roster in 2011. After his 2011 release, he wrote on his Facebook page that he needed time to heal from a concussion.

"I'm gonna take a little break away from MMA, let the brain heal from my concussion, and get the passion/fire back."

He switched to boxing after his final pro MMA fight in July 2016.

Hague's last fight before Friday's bout was in early April against Jared Kilkenny. He lost by TKO (Technical Knock Out).

Hague trained at UFC Gym in Sherwood Park at least six times a week, said the gym's owner, Alicia Landry. He usually stayed for two to three hours to lift weights and work on his conditioning.

"Locally, he's iconic," Landry said.

"The MMA industry in Edmonton is very small and it's very tight knit," she added. "Everybody has each other's backs, regardless of past issues."

Though he boxed at another location, Hague offered one-on-one evening classes at Landry's gym.

"He was probably one of the most positive people I've ever met," she said. "He was just happy to do whatever he could to help anybody — I've never seen him have a bad day.

"If he saw somebody struggling with pads, he'd step in and volunteer his time to set them on the right path."

Hague — a Grade 4 English teacher at École Bellevue School in Beaumont, Alta. — had planned to lead a summertime sports camp at the gym. "The students just adored him," Landry said. "He's a big teddy bear, that guy."

Melanie Lubovac of KO Boxing wouldn't comment on the event when reached late Saturday after Hague's family said he was in critical condition, but Lubovac said a statement would likely be issued Sunday or Monday.

Support will be available for Hague's students when they return to class Monday, the school's principal Jennifer El-Khatib told CBC News.

"Our hearts are heavy," she wrote in a statement Sunday.

"Mr. Hague was a beloved teacher and staff member. His students loved him and looked up to him, and he was an important part of our school community."