The Reuters news agency says the secret IOC survey revealed only 56 percent local support for bringing the games to Japan. That number is dramatically lower than the 70 percent support Tokyo's bid team claims to have in its own poll.
The IOC commissioned polls in each of the cities competing for the 2016 Games. The results have been shared with bid leaders but not publicly released.
Chicago's Olympic planners say their polling shows 78 percent of people want the Games to come to town. A Chicago 2016 spokesman declined to say whether the IOC poll found different results.
Chicago is competing with Tokyo, Rio de Janeiro and Madrid for the right to host the Summer Games.