The Court of Arbitration for Sport has dismissed an appeal by 47 Russian athletes and coaches against a ban on participation in the Winter Olympics.
The Russians had argued that they had been wrongfully excluded from the games by the International Olympic Committee.
It came just hours before the Winter Olympics opening ceremony on Friday.
The decision comes amid a long-running row over Russian doping which has seen Russia banned from the games, but 169 Russians will compete as independents.
But 169 Russians have been invited to compete as independent athletes.