The US Senate has accused major banks of allowing former Chilean dictator Augusto Pinochet to set up a network of accounts to conceal his wealth.
The banks are accused of helping Pinochet hide assets
The allegations are contained in a report by a senate sub-committee, which names Citigroup, Bank of America and seven other institutions.
Bank officials say the accounts were opened under false names, and have vowed to co-operate with investigators.
Thousands died under Gen Pinochet's military regime in the 1970s and 1980s.
He is also being investigated in Chile over allegations of both human rights abuses and embezzlement of state funds.
The Senate report found that some of the banks allowed Gen Pinochet to use assumed names on accounts, arranged international wire transfers and set up offshore companies.
It says the purpose was to hide an estimated $30m from US investigators as well as international prosecutors who were trying to seize his assets.
Some of the banks, including Riggs and Citigroup, had a relationship with Gen Pinochet going back 25 years, the report says.
All of the accounts have since been closed.
Senator Carl Levin said the report illuminated "another chapter in a very tawdry episode in American banking".
In January Riggs Bank pleaded guilty to failing to report suspicious activity relating to accounts held by Gen Pinochet and the government of Equatorial Guinea.
The bank later agreed to pay $8m to victims of crimes committed during his regime.
The BBC's Ian Pannell in Washington says there will now be pressure on the others to do likewise.
In a statement, Citigroup said its accounts for the general were opened "with false documentation using pseudonyms".
Bank of America, for its part, said it had "cooperated fully with the subcommittee in its investigation, conducted a thorough internal investigation and submitted documents as requested".