The catwalk queen, who's been dating The Kills' guitarist for two years, is being linked to Living Things star Eve Berlin.
The American rocker's brother and the band's lead singer Lillian said that he had caught Eve and Moss nude and in a compromising position.
"Walking in on my brother and Kate Moss with their clothes off, that was very awkward," the Sun quoted him as saying.
"I don't like to look at my brother naked. Between my brother being naked and seeing Kate Moss naked with my brother, that was very awkward," he added.
Lillian has claimed that the encounter took place last June after the pair met on a trip to Berlin. (ANI)