By Andrew Downie
SAO PAULO (Reuters) - At least six of Brazil's World Cup arenas, including the Maracana stadium where the final was staged in 2014, are under scrutiny in a wave of new political corruption investigations launched by the country's Supreme Court this week.
Newly unsealed plea bargain testimony from engineering group Odebrecht cited irregularities at the Corinthians Arena in Sao Paulo, the National Stadium in Brasilia, the Pernambuco Arena in Recife, the Castelao Arena in Fortaleza and the Amazonia Arena in Manaus, along with the Maracana stadium in Rio de Janeiro.
Supreme Court Justice Edson Fachin began releasing his findings on Tuesday, but details are still emerging from the hours of recorded testimony from 77 current and former executives at the politically connected Odebrecht Group.
Evidence that builders and politicians collaborated to fix contracts reinforces suspicions that many of the 12 stadiums built or renovated for the 2014 World Cup were overpriced.
The Maracana was slated to cost 700 million reais ($225 million) but eventually topped 1 billion reais. The Corinthians arena in Sao Paulo was originally going to be a smaller stadium built for 350 million reais but the cost rose above 1 billion reais after it was decided to hold the opening match there.
Brasilia's National Stadium, which was merely renovated for the tournament, was the most expensive of all, at 1.4 billion reais.
The Odebrecht executives gave their testimony as part of a settlement with U.S., Brazilian and Swiss authorities in the biggest-ever foreign bribery case. Politicians named in the testimony have denied any wrongdoing and now have the opportunity to present evidence of their innocence.
According to testimony released by the Supreme Court, at least five Odebrecht executives confirmed payments were made to secure what they called "an unfair advantage associated with work on the Maracana stadium."
In Pernambuco, Manaus and Fortaleza, Odebrecht and another construction company collaborated to "frustrate the competitive character of the bidding process."
Companies also combined to inflate the price of a roof for the National stadium, according to the testimony.
Brazil's biggest-ever graft investigation, which this week produced probes into nearly 100 politicians, has already jailed dozens of business leaders and money launderers over billions of dollars in bribes for public works deals with state companies.
($1 = 3.14 reais)
(Reporting by Andrew Downie; Editing by Brad Haynes, Bernard Orr)