The Boston-based State Street Corp. revealed this Tuesday that it is under investigation by the SEC. The agency is looking into allegations that the bank overcharged pension funds for foreign exchange transactions.

If this investigation prompts charges, it will be just the latest in a long line of legal action taken against State Street in connection with its pension-fund management. The State of Massachusetts opened an investigation against the company late last month, and California and Arkansas already have filed suit for millions in damages.The California brief alleges that State Street would charge pension fund the highest rate of the day, even if trades at the same time were at a lower rate, costing the funds millions. Washington state settled with State Street for over $11 million last October.

State Street says it is cooperating with the investigation. The SEC did not provide a comment.  To read more, see articles here or here.