By Gary Duffy
BBC News, Sao Paulo
Tours of Brazil's poor, crime-ridden favelas have been running for years
Police in the Brazilian city of Rio de Janeiro are to investigate claims that tourists visiting some of the city's shanty towns are being offered a chance to meet armed drug dealers.
The police say they want to establish if the lives of tourists are being put at risk, but the company involved has defended its policy.
For many years guided tours of favelas or shanty towns have been an option for people visiting Rio de Janeiro.
Distinctive green coloured open four-by-four vehicles can often be seen stopping at hotels to pick up tourists who want to see the other side of life in the city.
More than one million of Brazil's poorest citizens are said to live in the sprawling favelas that are spread around Rio.
While many are dominated by drug gangs and extremely dangerous, others are considered safe enough to visit, though some critics have argued this aspect of tourism in the city is distasteful and ill-conceived.
The Brazilian newspaper Folha de Sao Paulo has now reported that one company offering these tours includes a chat with what it calls an "armed soldier".
A journalist from the paper, who was posing as a tourist, went on a tour of Rocinha - said to be the largest shanty town in Latin America.
While there he was introduced to an armed man belonging to the faction that controls the sale of drugs in the area, who explained he had already spent nine years in jail.
The gunman said his principal worries were the police and rival drug gangs.
Another man armed with a machine gun told how he worked 12-hour shifts and earned $180 (£90) a week.
The tour company has been accused of glamorising criminal activity.
But the unrepentant owner of the agency involved says the presence of armed men in the favelas is the fault of the authorities, and they should clean up their own act before starting to criticise him.