The 39-year-old woman, originally from the north of England, is said to have found herself held captive at an isolated house in the southwestern commune of Rosarno, Calabria.
She had travelled there with Mamadou Jallow, who she originally met on Facebook.
When they arrived in the country, 37-year-old Jallow allegedly emptied her bank account, stole her phone and took her prisoner.
He then repeatedly raped her and allowed another two men to abuse her over the course of a fortnight.
Eventually she was able to get hold of her phone and call her family for help.
They had already contacted Interpol, having not heard from her for several months.
Police traced the call to the house and called her phone, convincing her to flee and giving directions to safety. Officers were said to have found her in a “terrible state”.
She told them she had originally gone to Germany for a face-to-face meeting with Jallow, but the pair fled the country after he stabbed a rival during a dispute over drugs.
Police have now arrested Jallow, originally from Burkino Faso, on suspicion of kidnapping, enslavement, aggravated and continued sexual violence, and theft.
The other two men – from Mali – are also being held in custody.
The case comes as a man is being tried in Milan for the alleged kidnap British glamour model Chloe Ayling.