When Nicholas Berg took an Oklahoma bus to a remote college campus a few years ago, the American recently beheaded by terrorists allowed a man with terrorist connections to use his laptop computer, according to his father. Michael Berg said the FBI investigated the matter more than a year ago. He stressed that his son was in no way connected to the terrorists who captured and killed him. Government sources told CNN that the encounter involved an acquaintance of Zacarias Moussaoui -- the only person publicly charged in the United States in connection with the September 11, 2001, terror attacks. According to Berg, his son was taking a course a few years ago at a remote campus of the University of Oklahoma near an airport. He described how on one particular day, his son met some terrorist people -- who no one knew were terrorists at the time." At one point during the bus ride, Berg said, the man sitting next to his son asked if he could use Nick's laptop computer. Government sources said Berg gave the man his password, which was later used by Moussaoui, the sources said. The sources said the man who used Berg's e-mail knew Moussaoui. But the sources would not disclose details of how the men were connected.