Updated from 1:37 p.m. EDTJohn Mack will find himself on the hot seat after all, answering allegations that he fed inside trading tips to a giant hedge fund. Morgan Stanley ( MS) said Friday that the Securities and Exchange Commission wants to interview Mack, the Wall Street firm's CEO, over the allegations that he passed on an improper tip about a possible corporate merger to Pequot Capital, a $7 billion hedge fund. "Yesterday, the SEC contacted John Mack and asked that he be interviewed regarding the hedge fund matter that has been widely covered by the media recently," Morgan Stanley's statement said. "John immediately responded that he is happy to meet with the commission staff, and he welcomes the opportunity to put to rest any issues surrounding this matter." The SEC's request to interview Mack comes just weeks after the allegations became the subject of a high-profile hearing on Capitol Hill. The Senate Judiciary Committee called the hearing after The New York Times ran a front-page story about a former SEC staff attorney, who claims his superiors put the kibosh on his investigation of Pequot and Mack. Attorney Gary Aguirre claims his superiors at the SEC stymied his investigation when he sought to take testimony from Mack. He also claims the SEC let him go because he was too aggressive in pursuing the allegations against Mack and Pequot. Up until now, SEC officials have denied squelching the investigation. Regulators said Aguirre didn't present enough evidence to justify calling Mack as a witness. The SEC's about-face on taking testimony from Mack could be a response to pressure from Capitol Hill or could reflect newly discovered information. A spokesman for the SEC was unavailable for comment. A spokesman for Pequot reiterated the hedge fund's claim that it has done nothing wrong. A spokeswoman for Morgan Stanley declined to comment beyond the statement. The law firm representing Aguirre, the Government Accountability Project, released a statement late Friday regarding the Pequot probe. Aguirre's attorney, Joanne Royce, was informed that the SEC was reopening the investigation into Aguirre's claims. "The SEC Inspector General informed Ms. Royce that it has reopened the investigation into Aguirre's charges of favoritism and retaliation and is seeking to interview Aguirre," the statement said.