Federal Bureau of Investigation agents raided the offices of three hedge funds as part of a high-profile insider-trading investigation, and more could be on the way, according to people familiar with the matter.

The offices of Diamondback Capital Management LLC and Level Global Investors LP were raided. Both hedge funds are run by former managers of Steve Cohen’s SAC Capital Advisors.

The third firm raided is Loch Capital Management LLC, based in Boston, people familiar with the matter say. Leonard Pierce, a lawyer for Loch Capital, declined to immediately comment.

“The FBI is executing court-authorized search warrants in an ongoing investigation,” said Richard Kolko, an FBI spokesman, who declined to comment further.

Loch had $750 million in assets as of the start of this year, according to SEC filings. The firm, run by brothers Timothy and Todd McSweeney, didn’t immediately return a message seeking comment. Leonard Pierce, a lawyer for Loch Capital, declined to immediately comment.

The McSweeney brothers are acquaintances with Steven Fortuna, a hedge-fund manager who pleaded guilty in the Galleon case and agreed to cooperate in that ongoing investigation.

Level Global Investors LP is a Greenwich, Conn., hedge-fund firm run by David Ganek, a former SAC Capital trader and art collector. He started Level Global in 2003 and earlier this year reported managing about $4 billion in assets.

(Read More: WSJ)