Russian President Vladimir Putin's back troubles stem from a recent bout of judo, according to the leader of the neighboring state of Belarus.
"I know he has this problem. He loves judo. He lifted a guy, threw him, and twisted his spine," Belarussian President Alexander Lukashenko told Reuters in an interview.
Lukashenko had been hoping to play ice hockey with Putin but the Kremlin leader postponed the match, he said.
"He tells me, 'We are not prepared yet to take on your team.' He has damaged his spine somewhere. In a judo match. He was on the mat and hurt his spine," Lukashenko said.
Putin's spokesman Dmitry Peskov declined to comment.
Putin, a judo black belt who began a six-year presidential term in May and turned 60 in October, was seen limping at an Asia-Pacific summit in the Russian port of Vladivostok in early September.
Three government sources told Reuters in late October that Putin was suffering from back trouble. Several foreign trips which had been expected around that time but were never officially announced by the Kremlin have not taken place, including a trip to India.
The Kremlin dismissed talk that Putin had a serious back problem and that he might require surgery. It acknowledged that he had suffered a sports-related injury but gave no details.
The Russian leader is expected to resume foreign travel in December, Kremlin sources say.