Nigeria's former Fifa member Amos Adamu has lost his appeal against a three-year ban over World Cup bid bribes.

The ruling from the court of arbitration for sport (Cas) has confirmed the Fifa ban and even said that the sanction was "relatively mild given the seriousness of the offence".

Adamu was banned by Fifa's ethics committee following a Sunday Times investigation when he was secretly filmed by journalists, posing as lobbyists, asking for US$800,000 to influence his vote for the 2018 World Cup.

Cas said in its ruling: "The Cas panel stressed that it was of crucial importance that top football officials should not only be honest but should evidently and undoubtedly be seen to be honest.

"With respect to the behaviour of Dr Adamu, the Cas panel was comfortably satisfied that he was far from actively and unambiguously refusing the improper offer set forth by the alleged lobbyists.

"In conclusion, the Cas arbitrators considered that the sanction imposed by Fifa was not disproportionate and was even relatively mild given the seriousness of the offence."

It is the first time Cas has been called on to rule on a sanction by Fifa's ethics committee. Mohamed Bin Hammam, the former Fifa member banned for life last year for bribery, has also appealed to CAS and the hearing will take place on 18 and 19 April.