The singer is at the centre of a riddle after workers at London's posh Intercontinental Hotel said she left a tub in her suite filled with claret liquid.
One housekeeper claimed the singer was "bathing in blood as part of a Satanic ritual".
She told website Truthquake: "Lady Gaga left large amounts of blood in the suite during a stay this summer. The incident was reported to the concierge, who was told to put it out of her mind."
An insider added: "All of the hotel's staff are convinced she was bathing in it or, at the very least, using it as part of one of her new costumes or weird stage routines."
Gaga, whose hits last year included The Edge Of Glory, was probably just washing off the fake stuff she uses on stage.
She could have taken the plug out though.