An executive of a hedge fund networking firm was arrested Wednesday on charges related to insider trading, part of a broad investigation of hedge funds by U.S. prosecutors.

A criminal complaint unsealed in U.S. District Court in New York said Don Ching Trang Chu, also known as Don Chu, promoted the services of his California-based firm, Primary Global Research, by arranging for inside information to be leaked to hedge funds.

Chu’s arrest stems from wiretaps and the cooperation of Richard Choo-Beng Lee, a hedge fund manager who pleaded guilty last year as part of the insider-trading prosecution of Galleon Group hedge fund founder Raj Rajaratnam and 22 other traders, lawyers and executives.

The government won a big victory in the Galleon case on Wednesday when a judge ruled that telephone conversations of Rajaratnam’s that were secretly recorded by the FBI were admissible as evidence at his trial. Rajaratnam has pleaded not guilty to charges of conspiracy and securities fraud and is scheduled to go on trial on Jan. 17.

Prosecutors have described the Galleon case as the biggest probe of insider trading at hedge funds in the United States. The investigation has widened to include subpoenas of several funds with billions of dollars under management.

In subpoenas served on SAC Capital Advisors and other hedge funds and mutual funds, authorities have asked for information about so-called “soft dollar” deals — an arrangement in which a hedge fund client executes trades through a designated brokerage that has some relationship with an expert networking firm such as Primary Global.

Expert networking firms are businesses that take fees to match up hedge funds with experts in particular industries such as medicine, engineering and technology.

The widening investigation heated up on Monday when FBI agents used court-approved search warrants to raid three hedge funds in Connecticut and Massachusetts.

Lee once worked for SAC Capital. There is nothing in Wednesday’s complaint that alleges any wrongdoing at SAC Capital. Authorities are looking at funds established by former associates of SAC founder Steven Cohen, according to lawyers and people familiar with the investigation.

A spokesman for SAC declined to comment. Chu’s lawyer, Jeffrey Plotkin, could not immediately be reached for comment.

The office of Manhattan federal prosecutor Preet Bharara said Chu, 56, of Somerset, New Jersey, was scheduled to leave the United States for Taiwan on Nov. 28. He is expected to appear in Manhattan federal court later Wednesday.

In charging Chu, prosecutors said he arranged for hedge funds to receive confidential information on companies including Atheros Communications Inc, Broadcom Corp and Sierra Wireless Inc.

Telephone calls between Lee and Chu from July 14 to August 28 last year were recorded by the FBI, according to the criminal complaint, which was signed by FBI agent B.J. Kang, one of the lead investigators of Galleon.

The complaint does not name the brokerage that hedge funds were directed to by Primary Global. However, Primary Global is the owner of a San Francisco-based brokerage called PGR Securities. A company representative declined to comment.

A check of the brokerage’s registration statement does not reveal any past regulatory infractions.

Prosecutors allege that in 2008 and 2009. Lee struck up a relationship with Chu while Lee was working at Spherix Capital, a now-closed San Francisco fund that Lee managed with Ali Far.

Both Lee and Far pleaded guilty to trading on inside information in the Galleon case and are cooperating witnesses.

Far worked at Galleon for many years. Lee is a former trader and analyst at SAC.

As part of his cooperation agreement, Lee agreed to tell prosecutors of any insider trading he engaged in at SAC, which he left more than six years ago.

Lee’s lawyer, Jeff Bornstein, said. “My client is and continues to be cooperating to the best of his ability with the U.S. attorney and the FBI. Beyond that I don’t have a comment on the specifics.”

Additional reporting by Emily Chasan; Editing by Ted Kerr and John Wallace