Florida prosecutors are investigating charges that a major New York bank hired to safeguard retirees' savings cheated them by overcharging for currency-exchange trades.

Attorney General Pam Bondi plans to take over a whistleblowers' lawsuit alleging that the Bank of New York Mellon defrauded Florida's pension fund with the secret markup on billions of dollars, collecting a higher currency-conversion price than it actually got and pocketing the difference. The whistleblowers filed a similar lawsuit in Virginia.

"On behalf of the state of Florida, we will not tolerate these actions and they will be held accountable,'' Bondi said in a statement.

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