The Court of Arbitration for Sport has confirmed that Legia Warsaw have failed with their appeal to be reinstated to the Champions League.
The Polish club was recently kicked out of the competition for fielding an ineligible player during their playoff tie against Celtic, despite beating the Scots 6-1 on aggregate.
Following the latest ruling, which comes after Legia's failed appeal to UEFA last week, Celtic will be allowed to retain their place in the tournament this season.
Celtic return to Champions League action on Wednesday when they face NK Maribor in the first leg of their final qualifying playoff.
CAS are due to assess the case in the next few weeks, though the governing body has revealed that Legia have requested that no sanctions be imposed on them or the player involved, and that UEFA pays financial compensation to the club.