A former trader-turned-informant secretly recorded more than 125 conversations with former colleagues for hedge fund firm Visium Asset Management LP and others spanning more than 200 hours, according to a court filing.

The informant, previously identified by Bloomberg News as junior trader Jason Thorell, spent more than two years cooperating with the U.S. Securities and Exchange Commission and FBI. He stands to receive a payout under the SEC’s whistle-blower program. The court filing identifies him only as "CC-1."

The case began as an investigation into whether portfolio managers at the $8 billion firm were fraudulently inflating the value of holdings in its credit portfolio. But it subsequently expanded to allegations that the firm was trading health-care securities on insider tips received from a former official at the U.S. Food and Drug Administration.

Stefan Lumiere, an assistant portfolio manager in the credit fund, is the sole remaining defendant in the case after two others pleaded guilty and the most senior executive charged, Sanjay Valvani, committed suicide.

The court filing, submitted by Lumiere’s defense lawyers early Tuesday, asks a judge to suppress certain evidence seized in a raid of his apartment. It also seeks an order compelling the government to identify co-conspirators in the case, claiming there are others beyond the two brokers who have been cited in court papers as "Broker-1" and "Broker-2."

The case is U.S. V Lumiere, 1:16-cr-00483, U.S. District Court, Southern District of New York (Manhattan).

This article was provided by Bloomberg News.