Seven banks have received subpoenas as part of an investigation into the alleged manipulation of the London Interbank Offered Rate, according to a source close to the case and company filings.

The banks that were subpoenaed by New York State Attorney Eric Schneiderman include JPMorgan, Citigroup, Barclays and UBS.

In a recent filing with the U.S. Securities and Exchange Commission, Citigroup said its subsidiaries “have received additional requests for information and documents from various U.S. and non-U.S. governmental agencies, including the offices of the New York and Connecticut Attorneys General.”

Source: CNBC.com. Reported by CNBC’s Jim Forkin.