Prosecutors in the United States have asked Goldman Sachs to explain its behaviour in the run-up to the global financial crisis.
The formal request by the Manhattan district attorney for information from the bank is the latest in a series of probes by regulatory authorities.
Although a subpoena is only a request for information and does not mean Goldman Sachs has done anything wrong, the bank's share price has fallen on the news, the BBC reports.
It comes just weeks after a powerful senate sub-committee accused Goldman Sachs of misleading investors and Congress.
Goldman Sachs says its testimony was truthful, but the committee's report alleges that Goldman Sachs steered investors towards mortgage securities it knew would fail.
