Jürgen Brähmer-Beibut Shumenov off

Light heavyweight titlist Jürgen Brähmer, citing illness, packed up and left Shymkent, Kazakhstan on Tuesday, forcing his unification fight with Beibut Shumenov to be called off, promoter Dan Goossen told ESPN.com.

Germany's Brähmer and Shumenov, who is from Kazakhstan but is now based in Las Vegas, were due to meet on Saturday.

Goossen, Shumenov's promoter, said he was skeptical of Brähmer's sudden departure. He said Brähmer did not alert anyone that he was leaving.

"We found out that he packed up and was leaving before we heard anything about him being sick," said Goossen, who sounded in despair after having arrived in Kazakhstan only hours earlier after a four-flight, 28-hour odyssey from Los Angeles. "He said he had diarrhea but there's a lot more to the story than him claiming that he's sick. So we're obviously very upset and going to discuss things with [Brähmer promoter] Peter Kohl on how this man would leave Kazakhstan without informing any of us. Peter says he didn't hear anything from him."

Kohl, who heads Universum Box-Promotion, was not in Kazakhstan but Goossen said, "Peter is trying to get him to reconsider and we're waiting to hear back from him, but I think we all know this fight isn't going to happen Saturday.

"Bottom line is he didn't inform anyone here that he was sick and we just happened to find out he had packed his bags and was on his way to the airport. If you're really sick you don't pack up and walk away. I'm trying to get to the bottom of this. But you just don't act that way if you're really sick. Right now there's a lot more I need to find out. Beibut is beside himself right now. I've never seen anything like it."

Universum said Brähmer and German Boxing Association chief Thomas Pütz, who was traveling with Brähmer, both suffered "acute gastrointestinal illness."

"A few hours after arrival in Shymkent, both came down with severe diarrhea with nausea and severe vomiting which lasted all night," Dr. Michael Ehnert said in a statement released by Universum. "This caused severe headaches and abdominal pain. Jürgen was particularly so weakened that he couldn't train and it's not possible for him to be able to compete for a world title in a few days.

"Due to the unclear cause and ambiguous symptoms, it was decided to arrange for an immediate return to Germany this evening to head directly to the hospital after landing for treatment. So far, we have only a vague suspicion of the cause. Jürgen and Thomas Pütz were eating together on Sunday afternoon near the hotel and that evening they complained about the first symptoms, which really hit them on Monday."

Said Kohl, "This is a big catastrophe. We, and above all Jürgen, are crestfallen. This fight would have written German boxing history. Now we hope that Jürgen and Thomas become healthy as soon as possible."

The deal for the 175-pound unification match had been in the works for a couple of months before being announced in mid-December.

The 27-year-old Shumenov (10-1, 6 KOs) was a 2004 Olympian for Kazakhstan before turning pro in 2007. He won his belt on a controversial split decision against Gabriel Campillo in a rematch of his only defeat in January. In his only defense, Shumenov survived a first-round knockdown to win a lopsided decision against previously undefeated Vyacheslav Uzelkov in July on ESPN2.

Brähmer (36-2, 29 KOs), 32, has made two title defenses, both in his home country. He outpointed Dmitry Sukhotsky 13 months ago and scored a fifth-round knockout of Mariano Nicolas Plotinsky in April.

Dan Rafael covers boxing for ESPN.com. Follow him on Twitter.