Playboy boss HUGH HEFNER’s girlfriends have upset officials in Monte Carlo, Monaco after illegally entering royal grounds without permission.

Pretty blondes Kendra, Holly and Bridgette were promoting their reality TV Show The Girls Next Door at the Monte Carlo Television Festival when they took time off to go sightseeing, and found themselves in big trouble.

The ladies smuggled a camera crew into the grounds of Monte Carlo’s Palace and were arrested by local police. Reports suggest the ladies were detained and later released after a warning.

Hefner, who was holidaying with the trio in Monte Carlo, was not part of their palace romp.