Benjamin Lawsky, New York's top financial regulator, has asked more than a dozen banks including Goldman Sachs Group Inc. (GS) and Deutsche Bank AG (DB) for documents related to their currency trading practices, a person familiar with the matter said.

Lawsky also requested information from Lloyds Banking Group Plc (LLOY), Royal Bank of Scotland Plc, Credit Suisse Group AG (CSGN) and Standard Chartered Plc (STAN), according to the person, who asked not to be identified because the investigation isn't public. Lawsky has asked for traders' e-mails and instant messages to review whether they manipulated currency rates, the person said.

At least 20 people have been fired, suspended or put on leave by banks since Bloomberg News reported in June that employees at some firms shared information about their currency positions with counterparts at other lenders. At least a dozen regulators and agencies on three continents are investigating the rigging allegations.

Spokesmen for Goldman Sachs, Deutsche Bank, Credit Suisse and Standard Chartered declined to comment, while spokesmen for Lloyds and RBS didn't immediately respond to phone calls and e-mails.

'Enforcer With Zeal'

Lawsky, the superintendent of New York's Department of Financial Services, has authority over financial institutions chartered in his state, including several non-U.S. banks that do business in the country. While Lawsky isn't authorized to bring criminal charges, he can make referrals to prosecutors, according to Bartlett Naylor, a lobbyist for Public Citizen, a Washington-based consumer group.

"You have a law enforcer with zeal who no doubt has numerous weapons, and he's prepared to deploy them on behalf of the law and on behalf of consumers," Naylor said in an interview. "The record shows that's missing in so many other places including the federal level."

In August 2012, Lawsky garnered attention when he made public statements about possibly revoking Standard Chartered's banking license over the bank's violations of U.S. sanctions involving dollar transfers to Iranian clients.

Standard Chartered's stock dropped 16 percent the day of Lawsky's comments. A week later, the bank agreed to pay $340 million to resolve the matter. Other regulators followed, and the bank agreed to pay an additional $327 million for the conduct in December 2012.

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