Half of Brazilians have said they are opposed to hosting the Olympics that begin in less than three weeks amid deepening concern over the high cost of the games, according to a poll published on Tuesday.

That is double the percentage who said they were opposed to Rio's hosting of the games when the same poll was taken in 2013.

The Datafolha polling institute survey published in the Folha de S.Paulo newspaper also found that 63 percent of those asked in the latest poll think the Olympics will bring more costs than benefits, up from 38 percent three years ago.

With a price tag of 40-billion reais ($12.3 billion), Rio's games will be held as a deep recession grinds through its second year and with unemployment at over 11 percent.

On the political front, Brazil's suspended President Dilma Rousseff is facing an impeachment trial and may be ousted just days after the Olympics end Aug. 21.

Rio de Janeiro state is one of Brazil's most indebted. Its governor in recent weeks had to declare a "state of calamity" to secure some 2.9 billion reais ($892 million) in federal emergency funds just to pay police and keeps hospitals open through the games.

Crime in Rio has been rising recently - though officials say over 85,000 police and soldiers will be on the streets to ensure safety, double the force London had during its 2012 games.

Yet the specter of a terror attack worries authorities, following the recent bloodshed in Europe, the United States and elsewhere.

Federal prosecutors meanwhile have said they are investigating allegations of corruption in several projects, including both Olympic venues and so-called legacy projects, such as the extension of a subway line and the refurbishing of a dilapidated port area.

Most of the building for the Olympics has been carried out by construction firms ensnared in Brazil's biggest corruption scandal, a kickback scheme at state-run oil company Petrobras [PETR4.SA].

Despite all that, the survey did find that 40 percent asked say they approve Rio holding the games. The remaining 10 percent said they were indifferent or did not respond to the question.

Datafolha interviewed 2,792 people across Brazil on July 14 and 15. The survey has a margin of error of 2 percentage points.

(Reporting by Brad Brooks; Editing by W Simon)