A few miles from where more than 10,000 athletes compete for the gold in every conceivable sport lies a world where girls as young as 9 are sold for sex for as little as $4.
"There is certainly evidence that points to an increase in child sex trafficking because of the Olympics. We know that the activities of sex gangs who recruit poor young girls have intensified in the months running up to the start of the Games in Rio," Matt Roper, founder of Meninadanca, a Belo Horizonte non-profit working to help at-risk girls in communities in Brazil, told Fox News Latino.
Along the BR-116, Brazil's longest highway known as "exploitation highway," is the zone where thousands of girls, some as young as 10, come from remote towns and become caught up in the sex trade.
According to the U.S. State Department of Trafficking in Persons Report, the Brazilian Federal Police estimates that 250,000 to 400,000 children are exploited in domestic prostitution, in resort and tourist areas, along highways, and in Amazonian mining brothels.
"In the days before the start of the [Rio] Games, a brothel specializing in underage girls, situated right in front of the Olympic Park, was busted in a police investigation. The girls were aged 13 to 15 and were taken to live at the house after being promised jobs as models, but then forced to have sex with rich clients," Roper told FNL.
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"The brothel was clearly gearing up for the influx of wealthy clients, especially Brazilians, arriving for the Games," he says.
In the shadows of swim competitions and medal ceremonies is a darker world. One where children are being brought to Rio to service tourists and fans.
"For teenagers who are taken away by the traffickers, it is often a trip without return, with girls finding themselves caught up in a dangerous world in which they become the property of the gangs, to be bought and sold like merchandise. Tragically, this could be one of the legacies of the Rio Olympic Games," Roper says.