The Babylon Moscow Escort Agency used an old picture of Girls Aloud on their adverts offering their premium escort services.
However the use of the image has now landed the agency in trouble with the band's management.
A source said to UK newspaper Daily Mirror: "It's an embarrassingly old picture of the girls, so the company figured they might get away with using it.
"But they failed to warn the band's record label they were using it and, theoretically, could get sued. Thankfully Cheryl and co have seen the funny side.
"They've been joking that Chezza's been getting off to Moscow in Simon Cowell's private jet... But in all seriousness, this is exactly the thing that needs to be monitored."