Sharing such images may seem despicable, but the photos are helping police in their investigation, the chief said.
On Sunday evening, the female Ohio University student reported "unconsenting sexual conduct" with a man between 1 a.m. and 6 a.m. that day on a street near the university's campus, about 70 miles southeast of Columbus, according to an Athens police report.
Athens Police Chief Tom Pyle told the Athens News for a story Wednesday that the witnesses may not have understood what they were seeing.
"It may have looked consensual to them," he said.
The photos show the couple against a bank window. Pyle told WBNS-TV in Columbus that the images and a video posted that night are essential to the investigation.
"While it certainly to the lay person would appear to be despicable that they're posting this information, it also assisted us in our investigation," Pyle told the station. "So a real double-edged sword."
Pyle declined further comment Wednesday when contacted by The Associated Press. He told the newspaper the woman who made the report and the man seen in the postings are cooperating with police.
Ohio University said in a statement it is assisting the investigation and providing support to the student who made the report.
Police in Steubenville in eastern Ohio used widely circulated photos of a 16-year-old girl raped by two high school football players last year in their investigation. A judge convicted the teens of rape in March.