JP Morgan, Deutsche Bank and Barclays are among a handful of banks recently subpoenaed in a joint New York-Connecticut probe of possible manipulation of inter-bank lending rates.

JP Morgan, Deutsche Bank and Barclays are among a handful of banks recently subpoenaed in a joint New York-Connecticut probe of possible manipulation of inter-bank lending rates, Reuters reported, citing an unnamed source.

New York attorney general Eric Schneiderman and Connecticut attorney general George Jepsen have been looking into the possible rigging and manipulation of Libor by global banks for months, their offices have said.

As part of that investigation, subpoenas were sent in recent weeks to Royal Bank of Scotland Plc and HSBC in addition to JP Morgan, Deutsche and Barclays, the source is quoted as having said. Earlier, UBS and Citigroup received subpoenas as well, the source said.

The subpoenas seek communication between executives related to possible collusion and other conduct that may have played a role in alleged rate manipulation, among other information, the report said.

Barclays has already paid a total of £290 million to settle charges that it manipulated LIBOR and euro LIBOR rates that are used throughout the world for financial products ranging from structured products to mortgages. Bob Diamond has resigned as Barclays chief executive in the wake of the affair. The revelations have damaged London’s reputation as a financial centre.