Cash found in an abandoned house last week almost certainly was part of the $70 million stolen last year in one of the world's largest heists, police said Thursday.

"We are convinced the money is part of what was stolen from the Central Bank in Fortaleza last year," said Romulo Berredo, head of the state's federal police. "We are 99.99 percent certain of this of this."

About $200,000 was found Saturday in the house in Natal, about 1,400 miles northeast of Sao Paulo.

Police said that three boys found 82,000 reals (US$37,000; euro29,000) in a bag when they chased a ball into a room of the house. One of the boys alerted his older brother, a police officer.

"Police then received an anonymous tip saying that later the same day, two men had been seen digging inside the house," the state Public Safety Department said in a statement earlier this week. "When police arrived, the two men fled leaving behind a box containing $150,000 that had been dug up from a false floor."

CountryWatch:Brazil

Thieves spent three months tunneling under a busy city avenue in Fortaleza, about 1,500 miles northeast of Sao Paulo, to break into the bank vault and steal the equivalent of $70 million in Brazilian currency, the real.

The heist took place sometime during the weekend of Aug. 6-8, 2005.

So far, 10 suspects have been jailed, but police believe others are still at large and say only $8 million has been recovered.

The Fortaleza heist was the biggest in history during peacetime until February, when thieves stole more than $90 million from a security warehouse in London.