Police said Monday that they've been unable to confirm that an alleged gang rape occurred at a University of Virginia fraternity house as described in a Rolling Stone article, and the school reinstated the group and its activities.

The University of Virginia said in a statement that the decision to reinstate Phi Kappa Psi was made after consulting with the Charlottesville Police Department. The Rolling Stone article described in graphic detail an alleged gang rape of a student at the Phi Kappa Psi house in 2012.

"The statement reads that we did not find any substantive basis to confirm the allegations occurred at Phi Kappa Psi, not that we said the assault did not occur. We are still investigating," Charlottesville Police Capt. Gary Pleasants said in an email to The Associated Press.

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After the article was published in November, the magazine issued a statement noting discrepancies in the story and apologizing.

Still, campus and fraternity leaders were put under pressure to adopt reforms, and police launched an investigation into the alleged assault.

Phi Kappa Psi was the first fraternity to agree to new rules, some of which address alcohol distribution at parties. Officials want to make it less likely for a drug to be slipped into drinks.

The new rules require that a minimum of three fraternity brothers remain "sober and lucid" at each fraternity function to serve as clearly identifiable monitors, with the addition of another sober monitor for every 30 members of the chapter. At least three of the monitors must be at least second-year brothers, and they are required to be standing in place where drinks are being served, as well as at the stairs leading to residential rooms. The fraternity member monitoring the stairs is required to have immediate key access to each room during the party.

"We believe that in the midst of this ordeal, there is an opportunity to move forward with important safety improvements. This has prompted us to take a closer look at ourselves and what role organizations like ours may play in this problem. It's opened all of our eyes to the problem of sexual assault," Stephen Scipione, president of the Virginia Alpha Chapter of Phi Kappa Psi, said in a statement issued by the university. "Now it's time to do something about it. As a fraternity, we are going to continue discussing that need in the coming weeks."

The spring semester at University of Virginia started Monday.