Paramount Pictures Chairman Brad Grey poses at the premiere of The Spiderwick Chronicles' at Paramount Pictures in Los Angeles in this Jan. 31, 2008, file photo. [Agencies]

The head of Paramount Pictures testified on Thursday he was unaware of any illegal acts by Hollywood's so-called private eye to the stars who worked on his behalf in two bitter movie industry lawsuits.

Brad Grey, CEO of Paramount Pictures and one of the most powerful players in Hollywood, is a prosecution witness in the U.S. government's bribery and wiretapping case against private investigator Anthony Pellicano.

Grey said Pellicano was hired by veteran lawyer Bert Fields, who was handling two lawsuits in 1999 and 2000 brought against Grey by comedian Garry Shandling and screenwriter Vincent "Bo" Zenga.