Several construction companies rigged their bids for 2014 World Cup stadiums, driving up costs by overcharging for the work, according to Brazil's anti-trust body.

”So far, there are indications that at least five bids related to World Cup stadiums were the subject of the cartel,” the anti-trust body CADE said in a statement.

Five stadium projects included Rio de Janeiro’s famous Maracana Stadium, where Germanydefeated Argentina 1-0 in the 2014 World Cup final.

The other stadiums named Monday in the statement were in the northeastern city of Recife, and in Belo Horizonte in the southeast. The other two stadiums were not named.

CADE said three other stadiums used in the World Cup also could have been tainted by corruption. They were named as venues in Fortaleza, Natal and Salvador – all cities in the northeast.

Brazil used 12 stadiums for the World Cup, although the governing body of world soccer FIFA required only eight venues.

Four of the new or remodeled stadiums were built in cities without top-division soccer clubs and have become white elephants. They included Cuiaba, Natal, Brasilia and the Amazon city of Manaus.

CADE said it obtained the bid-rigging information in a leniency agreement with construction company Andrade Gutierrez. It said the companies worked with an ”anti-competitive agreement” to rig bid prices.

Reports have been widespread about corruption linked to World Cup stadiums. Investigations are also on-going involving construction projects tied to this year’s Olympics in Rio de Janeiro.

An analysis last year said Brazil spent about $3 billon on new and refurbished World Cup stadiums, with 90 percent of the funding being public money. Reports say Brazil spent about $15 billion overall to organize the World Cup, and about the same on the Olympics.

The expenditures have been widely criticized as Brazil has plunged into a deep recession with several states – including Rio de Janeiro state – being months behind paying public service workers like teachers and hospital employees.