The arrests were made after the mother of the other girl, 15, became suspicious and hired a private investigator, Il Fatto Quotidiano said on Tuesday.
Her daughter was reportedly lured into prostitution last May via the website Bakeca Incontri, which is said to connect people 'for friendships and relationships'.
It was here she met the younger girl, who convinced her to become a prostitute after saying she could earn €300 for each customer, Il Fatto reported.
When the 14-year-old’s mother found out about her daughter’s prostitution, she reportedly decided to cash in and take a cut of the profits.
The older girl had been living alone, although her mother received an anonymous tip-off about her daughter’s activities, the newspaper said. After compiling evidence from a private investigator, she went to the police.
The five arrested, aged between 29 and 43, are accused of exploitation and aiding and abetting child prostitution. One, who allegedly sourced clients for the girls, is also the owner of the Rome appartment.
The men who had sex with the child prostitutes are also under investigation, Il Fatto said.