NEW YORK (CBSNewYork/AP) — Federal prosecutors in New York say three Chinese nationals profited from insider information about mergers and acquisitions after hacking into the networks of law firms working on the mergers.

U.S. Attorney Preet Bharara says the three men made over $4 million in profits by buying stock in companies that were about to be acquired and then selling the shares after the acquisitions were announced.

He says they acquired the insider information between April 2014 and late 2015 by hacking into the email systems of international law firms with offices in New York.

Defendant Iat Hong was arrested Monday in Hong Kong. Defendants Bo Zheng and Chin Hung have not been arrested.

Information about attorneys for the defendants wasn’t immediately available.

The targeted law firms aren’t named in the indictment.

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