In just a few minutes driving along a road on the outskirts of Milan in northern Italy, we counted 20 women, almost all African, standing by the kerb.
By Polly De Blank
BBC Africa Live, Milan
It was a cold night, but you wouldn't have guessed it from the outfits they were wearing.
We got out of the car, and approached one Nigerian woman who called herself Gioia - Italian for "Joy".
She was pretty beneath her heavy make-up. We asked her if we could talk to her.
"Maybe later," she said. It was Saturday night, and we weren't the only people cruising the roads.
It is estimated there are between 10,000 - 20,000 Nigerian prostitutes working in Italy today.
Almost all come from Edo state in southern Nigeria.
As yet, no research has been done into why so many come from this one state, but the route may have originally been established by Nigerian women who came over to southern Italy to harvest tomatoes during the 1980s.
Many Nigerian prostitutes do not see the money they earn
Valentina's story is typical. An old friend offered to bring her to Italy.
"He said finding work here was no problem, there were lots of different jobs I could do like working in a supermarket. I'd even be able to continue my studies," she said.
"I'd just finished secondary school, but it's very difficult to go to university in Nigeria. It's very expensive."
Promises of good jobs and education lure women like Valentina away from Nigeria.
The women in turn agree to repay hugely inflated costs for arranging documents and transport. But it's often not until they arrive in Italy that they are told that they will have to prostitute themselves in order to pay off the debt.
Valentina is not her real name. If her identity was revealed she would be in danger from the highly organised criminal gangs who traffic Nigerian women.
There is increasing evidence that the Nigerian criminals are becoming connected with Italian and other European Mafia.
In addition to the transport costs, the women are normally forced into paying hundreds of Euros a month in "rent" for the spots on the road that they solicit from.
Tomissi (again not her real name) is a shy, clever Nigerian who said she was 20 but looked at least two years younger.
After being brought to Italy last year, she had to sell her body on a lonely stretch of motorway outside Turin, and hour and a half west of Milan.
She ran away a couple of weeks ago.
"I used to have to have sex with many different men. As many as wanted to have sex with me. Maybe five, maybe ten different people a day," she said in a quiet voice.
"Some would pay me 20 euros, some would only pay 10. If I was really lucky I'd get 30 euros, that's about $35."
Tomissi was working for a "friend" of her mother's, who she said would beat her with a broom if she wasn't working hard enough.
Between January and March, about 20 prostitutes were killed in Italy, according to Amici di Lazarro, a group which gives legal and health advice to sex workers.
"About a month ago a girl was killed by a car full of drunk people. For a week all the other girls did not go into the street, because they were in mourning for her," said Paolo Botti, president of Amici di Lazarro.
Tomissi didn't see a penny of her earnings. According to Ibironke Adarabioyo, author of a recent book on the phenomenon, this is common.
"Just last week I met a woman who'd paid back 45,000 euros. All this time she wasn't allowed to send any of the money home".
According to Eki Igbinedion, the wife of the governor of Edo State who has her own charity helping women like Tomissi on their return, "over 50% of women don't know the gravity of what they're doing. If you go to any street in Nigeria and just say I'm going to take you abroad, it's like manna from heaven".
For those who manage to repay their debts, the money they send home can make all the difference.
But having worked with hundreds of women who've been prostitutes, Ibironke is adamant that the price is too high.
"Young girls should be careful. It's a hell they're going through here. It's hell"
Tomissi would like to add her own words of warning: "My advice to any girls who are thinking about coming to Europe is: Don't come.
"The madams say there's work here but they're lying because the only work here is prostitution. They're deceiving us Africans, and it's not fair."