Sao Paulo, Dec 8 (EFE) Thieves stole 10 million reais ($5.7 million) from an armoured-car company here in Brazil's largest city using a tunnel they dug over the course of four months, the police said.

The theft was carried out Sunday afternoon and so far police have not made any arrests, the police told reporters.

The thieves got into the company headquarters through a tunnel 150 meters long and one meter in diameter dug from a house they had bought four months ago in the Vila Jaguara neighbourhood that is separated from the firm where the funds were being kept.

The thieves said they were doing renovations and even painted it recently, so that local residents would not notice any movement of earth and materials into or out of the house.

Once the tunnel was finished, they waited until Sunday afternoon, when the attention of virtually all Brazilians was riveted on the national professional soccer championship, to break into the company offices and take the money.

One of the firm's security guards told the police that Sunday afternoon he heard a crash, but he thought it was fireworks that some fans were shooting off when their team scored a goal.

Inside the company, authorities found a tunnel map and several currency bills that apparently the thieves had let fall to the floor and not gathered up.