A French judge investigating Tokyo's alleged vote-buying for its bid to host the Summer Olympics labeled a Japanese probe into the claims "limited" and having "many flaws," according to the sources with knowledge of the matter.

The preliminary judge made the observation in Paris in December 2018 when questioning Tsunekazu Takeda, then-president of the Japanese Olympic Committee, the sources said Saturday. Takeda also headed the Tokyo Olympic bid committee.

It is the first time details about the exchange between the judge and the 73-year-old Takeda have come to light. A special investigative team from the Tokyo District Public Prosecutor's Office questioned Takeda and others in 2017 at the request of the French authorities.