(CNN) -- A Spanish National Police investigation into two Madrid prostitution rings led to the rescue of a captive 19-year-old woman who was tattooed with a barcode on her wrist after she tried to escape the ring, authorities said Saturday.
The bar code served as a form of identity for the woman and as certificate of "ownership" by one prostitution ring, and beneath the bar code was also tattooed the amount of money she owed the ring, police said.
Held hostage by a pimp, the woman had multiple lesions from being beaten and whipped, and her head and eyebrows were shaven because she tried to flee, police said.
In all, police disbanded two prostitution rings along Madrid's Montera Street that were operated by two Romanian nationals -- an uncle and his nephew -- and authorities arrested a total of 22 people, including the two relatives, in Madrid and Getafe, police said.
When the 19-year-old woman tried to escape, the uncle advised the nephew to tie the woman to a radiator and not feed her, police said.
Among items seized by authorities were three illegal firearms, numerous swords and machetes, gold jewelry, five automobiles and $185,696 in Euros, more than half of which was hidden in a double roof of the home of one ring leader, police said.
The ring leaders forced women, including underage girls, into prostitution, and members of the rings collected the money and controlled the rented floors of buildings where the women were forced into prostitution, police said.
The prostitution ring members referred to the women as "packages," "suitcases," or "bicycles," police said.