CHARLOTTESVILLE, Va. — The police here said Monday that they had found “no substantive basis” to support a Rolling Stone magazine article depicting a horrific gang rape at a University of Virginia fraternity house and that a four-month review had identified serious discrepancies in the account by a woman identified as Jackie, who refused to cooperate with their investigation.

After a review of records and roughly 70 interviews, Police Chief Timothy J. Longo Sr. said at a crowded news conference here, his investigators found “no evidence” that a party even took place at the Phi Kappa Psi fraternity on Sept. 28, 2012, when the rape was said to have occurred. Instead, he said, there was a formal that night at the house’s sister sorority, making it highly unlikely that the fraternity would have had a party on the same night.

Despite “numerous attempts,” he said, his officers were unable to track down the man Jackie had identified as her date that night. And several interviews contradicted her version of events. The chief said he was suspending, but not closing, the investigation, and he left open the possibility that some kind of assault might have occurred, saying additional information could still come to light.

“We’re not able to conclude to any substantive degree that an incident occurred at the Phi Kappa Psi fraternity house, or any other fraternity house, for that matter,” Chief Longo said. “That doesn’t mean something terrible didn’t happen to Jackie on the evening of Sept. 28, 2012. We’re just not able to gather sufficient facts to determine what that is.”