Mustafina led her team to gold at the Rotterdam World Championships, then won the individual all-around in commanding fashion -- her total was more than a point over second-place finisher Jiang Yuyuan of China.
Mustafina qualified to all four event finals and earned silver medals on vault, bars, and floor.
It would be in no way out of character that the leopard-petting, often shirtless president would get to see his girlfriend perform this Olympic honor.
(Photo by Andrew Toth/Getty Images)LONDON, ENGLAND - APRIL 26: Rupert Murdoch (L) is driven from The Royal Courts of Justice with his wife Wendi Deng Murdoch and son Lachlan after giving evidence to The Leveson Inquiry on April 26, 2012 in London, England.
SEE ALSO: Emotional baggage: Vladimir Putin ribs John Kerry over carrying his own luggage Rumors have "been floating around for years" since Putin's 2014 divorce from then-wife Lyudmila Putina, according to the report.
The pair share two daughters -- Maria, 30, and Yekaterina, 29.
Miss Kabaeva, 31, has been rumoured to be in a relationship with Mr Putin for several years, but the Kremlin has never acknowledged any link between the pair.
Friday's unconfirmed reports about a new child were the latest in a series of rumours to circulate since Mr Putin, 62, cancelled a planned trip to Kazakhstan on Wednesday.