The first 25 athletes from Russia and Belarus have been authorized by an IOC commission to compete at the Paris Olympics as neutrals.
Athletes in wrestling, weightlifting, road cycling and trampoline gymnastics have so far been given places in the Games from July 26 to August 11.
However, the International Olympic Committee's three-member review panel did not grant clearance for the Summer Games to four taekwondo fighters from Russia and one from Belarus. An IOC statement on Saturday did not explain why.
Due to Russia's war on Ukraine, which is supported by Belarus, there has long been a debate about the Olympic participation of their athletes.
To be eligible as neutrals, athletes must have no connection to the army or security forces and must not have actively shown their support for the war in Ukraine. They must also follow anti-doping guidelines.
As an additional condition, the IOC requires all athletes to make a written commitment to the Olympic Charter and thus also to the "peace mission of the Olympic Movement."
Russians and Belarusians are only allowed to compete in Paris under a neutral flag, with no national symbols or anthems. They are both banned from team sports and will also not be part of the opening ceremony.
The IOC recently expected a total of around 50 Russians and 28 Belarusians to be admitted to Paris.