[ by Melanie Gretchen ] An unnamed Goldman Sachs executive came under inquiry during a hearing in the case of Rajat Gupta, who is accused of leaking material confidential information to Raj Rajaratnam that he learned during bank boardroom discussions.  Speculation is growing that Matthew Korenberg, an investment banker at the firm, is that unnamed executive under investigation by federal prosecutors in California.  It's believed that, if he did leak confidential information to Rajaratnam's Galleon Group, it would have been about health care deals. Criminal Investigation. The United States attorney’s office in Los Angeles is looking into whether Mr. Korenberg, who's based in San Francisco, tipped off Galleon about health care mergers.  So far, Mr. Korenberg has not been accused of any wrongdoing.  John Hueston, with Irell & Manella and a former lead Enron prosecutor, is representing Mr. Korenberg.  He maintained his client's innocence, stating: "For more than 2 years, the government has pursued an investigation with nothing to show for it.  There has never been any allegation of any tipping or insider trading by Matt Korenberg." Goldman Career. Mr. Korenberg, a managing director since 2009, is at least the 3rd Goldman executive under investigation as part of the government’s insider trading inquiry.  The other two are:  (i) Goldman salesman David Loeb, who has a business relationship between the Galleon Group;  and, (ii) Henry King, a technology stock analyst at Goldman. Federal prosecutors in L.A. have been examining Galleon’s trading in at least 2 health care companies that used Goldman to advise on large merger transactions :  a takeover of Advanced Medical Optics by Abbott Laboratories in 2009, and MedImmune’s acquisition by AstraZeneca in 2007. Mr. Korenberg worked on a Goldman team that advised Advanced Medical Optics, where shares jumped 150% after the deal was announced.  One of his acquaintances, Paul Yook, a former Galleon employee who focused on health care stocks, also is under investigation.  He worked as a health care investment banker at Goldman earlier in his career. Drawing Attention Away From Mr. Gupta. Ahead of Mr. Gupta's 5/21/12 trial, attorney Gary Naftalis said during a court hearing last month that the government had secretly recorded telephone conversations of a Goldman executive discussing confidential information about Intel and Apple with Mr. Rajaratnam.  This and any other evidence of other supposed Goldman tipsters could help in Mr. Gupta's defense, specifically by creating doubt in the jurors' minds as to who at Goldman - Director Gupta and/or several Goldman employees - actually leaked inside information to Mr. Rajaratnam.  [C-I: Innocent until proven guilt beyond a shadow of a doubt!] As Gupta's attorney, Mr. Naftalis, has repeatedly said:  "The wrong man is on trial." [Dealbook, 4/26/12].