Roberson, 23, is named in a complaint filed with the Paradise Valley, Ariz., police department. His accuser, a female alumnus of Kansas State and a resident of Kansas, claims he attacked her at about 3:30 a.m. this morning at the team's hotel, the Scottsdale Plaza Resort.
However, Lt. Ron Warner of the Paradise Valley Police Department said Roberson has not been formally charged.
"No physical arrest is expected at this point," Warner told Bucknuts.com. "No physical evidence was found in the room. There were no evident physical injuries to the victim. She was examined medically and we await the results of that exam next week."
According to Warner, his department would then turn over its files to Maricopa County prosecuting attorney Rick Romley's office for a determination as to whether criminal charges will be filed.
"That would be determined by our county attorney if there is sufficient evidence to support a charge," Warner said.
Warner said Roberson told police that he had consensual sex with the alleged victim. The room involved was neither that of Roberson nor the woman.
Warner says police decided to issue a news release on the situation after a media inquiry.
As of 11 p.m. Eastern time, there had been no definitive announcement on Roberson's status for Friday's Fiesta Bowl game against Ohio State.
KSU athletic director Tim Weiser did meet with the media briefly on Thursday to discuss the matter.
"This morning we learned there was an incident that occurred," Weiser said. "(Head coach Bill) Snyder and I visited about that and as the process unfolds and we begin to learn more about the situation, then we'll act accordingly. At this point, we're letting the legal system go through its course.
"For those of you who know Coach Snyder, you know we have a great deal of trust in him. He has proven many times that he is more than capable of handling situations that come up within his football program.
"Will Ell play? That's a decision coach will make. I think at an appropriate time information will be shared about that. But we're not to that point yet. We're still in a fact finding mode. That's not my call. I know how (Snyder) deals with situations and I know he'll do the right thing."
There has been speculation that Roberson would at least be guilty of a curfew violation. Snyder told reporters his team had a 3 a.m. curfew earlier in the week and it was reported that Wednesday night's curfew was 11 p.m. But Weiser said he was unaware of a team curfew.
Lt. Warner told Bucknuts.com he met with Kansas State's chief of police, who is heading up the university's security detail for the bowl, at about 4:30 a.m. Thursday to discuss the investigation. It is reasonable to assume that Snyder knew of the ongoing investigation when he met with the media at 8:30 a.m. Roberson's status was not discussed at the media session.
"They were certainly aware of it," Lt. Warner said.
According to Lt. Warner, he was summoned to the hotel by Gordon Richards, head of security at the Scottsdale Plaza Resort.
"The victim reported it to the security officer at the hotel," Lt. Warner said. "There is evidence to support that they (Roberson and his accuser) knew each other previous to this incident. But there is no indication there was a sexual relationship."
Both Roberson and his accuser were interviewed at the Paradise Valley police headquarters. Roberson was questioned from noon until 2 p.m. The Kansas State team held its final practice at Sun Devil Stadium at 4 p.m. It is unclear whether Roberson attended that practice session.
A collection of media members covering both teams ventured to the K-State team hotel early Thursday evening seeking an update on Roberson's status, but were turned away and escorted from the grounds by hotel security.
Roberson was the driving force behind Kansas State's 11-3 Big 12 championship team this year. The three-year starter earned third-team All-Big 12 honors after rushing for 943 yards and 13 touchdowns and throwing for 2,251 yards and 24 scores.
If Roberson is ruled ineligible for the Fiesta Bowl, Kansas State would likely turn to senior Jeff Schwinn. Schwinn started two early season games while Roberson was injured, including the loss to Marshall. For the year, the 6-2, 205-pound Schwinn completed 37 of 68 passes for 563 yards with one touchdown and three interceptions.