Nikos Aliagas, who was presenting the awards ceremony, explained that an error had taken place in the vote-counting.
However, Perry, nevertheless, correctly collected the best international album prize.
Enrique Iglesias, the Pussycat Dolls and the Jonas Brothers were among the other stars that received awards at the ceremony.
French singer Christophe Mae was honoured with trophies for the best French song and for the best French male singer, and his compatriot, Mylene Farmer, claimed the award for best French album.
Chris Martin from Coldplay sang a song, and American R&B star Akon, as well as soul singer Seal, alos gave performances.
