The young woman and the Frenchman were apparently subjected to a six-hour ordeal by three men after flagging down a public transit van in the Brazilian city.
The horrific crime has sparked fear among visitors to the metropolis, which is set to host next year's football World Cup as well as the 2016 Olympics.
A few minutes after the pair of tourists boarded the mini-bus on Friday night, the operators ordered the other passengers to get off and inflicted a 'party of evil' on the couple.
The three assailants took turns raping the woman and beating the man, whom they handcuffed and sometimes struck with a metal crowbar, police investigator Alexandre Braga said yesterday.
The men split up the driving, ending up in Rio's sister city of Niteroi across, where they went on a spending spree with the foreigners' credit cards.
Once they hit the limit on both cards, spending around $500 at gas stations and convenience stores, the suspects drove the pair back to Rio and forced the woman to fetch another credit card, Mr Braga said.
He said that she did not dare call for help at this point 'because the young man was still under the suspects' control and she feared something even worse might happen to him'.
Around six hours after they were kidnapped, the tourists - both in their early 20s - were dumped by the side of highway 30 miles away from Rio.
They managed to reach a consulate, where staff helped them contact police. The woman has returned home, while the man is still in Brazil helping officers with their inquiries.
Wallace Aparecido Souza Silva, Carlos Armando Costa dos Santos and Jonathan Foudakis de Souza have been arrested on suspicion of the crime.
'The victims recognised the three without a shadow of a doubt,' Mr Braga said. The men's mug shots were also recognised by another woman who said she'd been raped by the three under similar circumstances last month.
Two of the suspects have confessed to Saturday's attack, while the third denies any responsibility.
Many are now asking whether Rio authorities, who have succeeded in cracking down on much of the city's drug violence, are up to the task of protecting the waves of tourists expected to flood the city during the World Cup and Olympics.
Some 2million people are also expected to flock to the city in late July for World Youth Day, a Roman Catholic pilgrimage that Pope Francis is scheduled to attend.
Observers said the attack came as a particular shock given that safety has improved at least in the city's tourist-friendly seaside neighbourhoods.
'No one expects to be attacked in Disneyland, handcuffed and roughed up,' said Alfredo Lopes, the head of the hotel association. 'Copacabana is our Disneyland.'
The suspects allegedly rented their van, which seats about a dozen people and has dark tinted windows, from the vehicle's owner, who has not been linked to the attack.
Rio's van services are widely reviled for their precarious safety conditions and reckless driving, as well as their links to organised crime.
Some vans are run by militias largely composed of former police and firemen who control large swaths of the city's slums and run clandestine transportation and other services. In general, tourists avoid the vans and opt for regular buses or taxis.
Australian visitors Emma Richardson and Jason Sestic said they have been taking extraordinary precautions throughout their weeklong stay in Rio.
'We've stayed well away from Copacabana and the beach areas at night,' Mr Sestic said. 'I'm a pretty paranoid person in general and I've heard enough stories about here to be really paranoid.'