Images double

Hi,

my website is in two languages. I don’t know how it happened, but suddenly all my images in the media library were double, one for each language. I checked the options and disabled the translation of media (I never switched it on). After disabling the translation of media I now want to get rich of the double images in the media library. I tried to delete one of the pair but that messes up: the other image isn’t working any more, too. Maybe because both images of the pair have the same source. What is the best way to clean up the media library?

Thanks,

Bastian