Marcus Bensmann, who made his name as an independent and outspoken journalist unafraid of criticizing the authoritarian practices of some Central Asian governments, had been robbed and severely beaten.
Bensmann, 38, was taken to a hospital in Astana with a concussion, a broken jaw, nose, and cheekbones, and severe frostbite.
His wife said she had no evidence that the assault was a result of Bensmann's work.
Bensmann was filming a documentary about Astana for the German television station WDR. He has worked for ARD/WDR in Moscow since 1997 and has written extensively for many German dailies and magazines about Central Asia.
Bensmann and his wife, Galima Bukharbaeva, were in Andijon on May 13, 2005, when Uzbek security forces opened fire on demonstrators, killing hundreds of people. Bukharbaeva has testified several times in the West about the events in Andijon as she witnessed them. Bensmann was forced to leave Uzbekistan shortly afterward, and has been unable to return to the country since then.
Bukharbaeva told RFE/RL's Kazakh Service that Bensmann's film about Astana was to show different aspects of the city.
"Besides the opera house, besides architects whom he wanted to talk to about new buildings, he wanted to show Astana's nightlife, so he went to a night club on Saturday night," she said. "And when he was leaving the club, as far as I know, he took a private taxi with two others already inside, and they were the ones who [attacked and beat] him."
Shanat Bintenov, a police chief in Astana working on the case, said Bensmann was the victim of a common robbery. Other observers, noting the severity of his beating -- which was unnecessary in robbing him -- have speculated that Bensmann may have angered someone in researching and filming his documentary or that someone linked to the Uzbek government -- of which he has often been very critical in his work -- may have ordered the attack against him.
Bukharbaeva said Bensmann is in "very serious condition" but that she was able to speak to him briefly before he was flown to Germany. Bukharbaeva said he has serious facial fractures but the greatest danger to his health is the frostbite, as he was left unconscious in temperatures of minus 20 degrees Celsius for several hours.
"I'm inclined to think that this was an unfortunate incident, most likely a criminal assault, a robbery," Bukharbaeva said. "I don't have any reasons, or indications, or suspicions that it was an organized attack with a political subtext."
(RFE/RL's Kazakh Service contributed to this report.)