IMF chief Dominique Strauss-Kahn spent much of Sunday locked up at the Manhattan Special Victims Unit and was forced to undergo forensic and scientific testing for possible DNA evidence on his skin or beneath his fingernails, said officials. Furthermore, investigation officials were worried that, since there was a good likelihood that Strauss-Kahn would be allowed to post bail, he would flee the country with the evidence on his person. Meanwhile, Strauss-Kahn’s accuser, a maid at the Sofitel New York hotel on West 44th St. in Manhattan, where the IMF chief was a guest, picked him from a police lineup at 4:30 p.m. Sunday, said police.