U.S. prosecutors are seeking testimony from three senior executives of the $15 billion hedge fund SAC Capital Advisors, the Wall Street Journal reported on Thursday.

The U.S. Attorney's office for the Southern District of New York issued subpoenas to SAC's president, chief compliance officer and head of trading, according to the Journal's report.

Others at SAC, including the firm's founder Steven A. Cohen, were asked last week to testify before a grand as part of the U.S. government's insider trading probe of the hedge fund, Reuters has previously reported.

The three who received the subpoenas are Thomas Conheeney, SAC's president, Steven Kessler, the chief compliance officer and Phillipp Villhauer, the head of trading, the Wall Street Journal reported.

An SAC spokesman declined to comment on the report.