NEW YORK ( TheStreet) -- Federal investigators have delivered 12 more subpoenas in a wide-ranging insider trading probe, Reuters reported Tuesday, citing anonymous sources.

Last month U.S. authorities were talking to employees at several firms , including Wellington Management, Janus Capital ( JNS), SAC Capital Advisors and Goldman Sachs ( GS) in connection with the probe.

Other hedge funds questioned by investigators are Diamondback Capital, Level Global and Citadel Investment Group, according to reports. The case appears to have sprung out of an investigation of Galleon Group, in which the government has already obtained 14 guilty pleas.

Reuters was unable to determine the people who received the subpoenas, the report stated.

A widespread crackdown on the hedge fund industry could hurt profits at Goldman, Morgan Stanley ( MS) Citigroup, Bank of America ( BAC) and other firms that do lots of business with hedge funds, but so far, investors in those institutions do not appear overly concerned about the issue. Though shares of these and other bank stocks dropped slightly the first trading day after the investigation was announced, the issue no longer appears to be affecting stock prices.

-- Written by Dan Freed in New York.
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