"Financial institutions of every major Wall Street bank were engaged in this," said Nanci Nishimura, an attorney representing the city.

The Contra Costa Times said the California cities of Los Angeles, Stockton and San Diego and San Mateo County have all filed similar suits.

The Contra Costa suit says the Department of Justice, the Internal Revenue Service and the Securities and Exchange Commission have been investigating the conspiracy, which involved rigging auctions in the municipal derivatives market, resulting in higher fees and lower interest returns for municipalities. The firms involved then issued secret payments to each other, the Times reported.

The suit points to Bank of America's immunity deal with the Department of Justice. "BofA ran into the Department of Justice with their hands up. They said, 'We're guilty. Give us some immunity and we'll spill the beans,'" Nishimura said.