The player was found guilty of match-fixing over the Euro 2008 qualifier between Norway and Malta, a game his country lost 4-0.
"Sammut has been banned from exercising any football-related activity for life by the UEFA appeals body," UEFA said in a statement.
A UEFA control and disciplinary body hearing in August handed out the original 10-year ban but the player and the governing body's disciplinary inspector requested an appeal and that was where the life ban was imposed.
FIFA, world soccer's ruling body, has been asked to make it a worldwide suspension.
Players union FIFPro had previously expressed concern the case against Sammut, 31, was based largely on the evidence of a member of a criminal gambling syndicate and questioned whether UEFA was capable of handling such an issue.
Sammut has 10 days to lodge an appeal with the Court of Arbitration for Sport (CAS).
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