(CBS) In a stunning sequence of events, the attorney for the woman who has accused Blackhawks star Patrick Kane of sexual assault said that the rape kit evidence bag that’s so critical to the case has been tampered with, while a lead Erie County official in western New York disputed the claim by saying all the original evidence is accounted for and properly sealed.

At a press conference in Buffalo early Wednesday afternoon, attorney Thomas Eoannou presented an empty evidence bag, showing that it had been ripped open. It was anonymously left on the doorstep of the accuser’s mother’s home and discovered Tuesday afternoon, Eoannou said. The evidence bag was confirmed to be authentic, as it was labeled with the alleged victim’s name, details on where the rape kit was used and the initials of the nurses who administered the kit, he said.

“I have my grave concerns as to what’s going on here,” Eoannou said. “That’s why we went public with it. That’s why we’re asking for an independent investigation by a separate law enforcement agency. Something seriously has gone amiss.”

Later Wednesday afternoon, Erie County commissioner of Central Police Services John Glascott denied that any evidence had been mishandled or that the chain of custody had been broken.

“All evidence related to this case that was given to Erie County Central Police Services by the Town Of Hamburg Police Department is accounted for and remains in its original packaging in the possession of Erie County Central Police Services,” Glascott said in a statement. “This includes the evidence in the rape kit and the packaging itself.

“This evidence has been analyzed and reports of that analysis sent to the appropriate agencies.”

In response to the statement from the Erie County official, Eoannou told CBS 2 in an email, “No one disputes that CPS has the evidence that was given to them. They wouldn’t accept evidence of it wasn’t in an evidence bag. The big question is how would they know it is the “original” bag?”

At his press conference, Eoannou strongly denied a report that surfaced over the weekend that said Kane’s DNA wasn’t found in the accuser’s genital area or on her undergarments.

“We don’t know what was found where,” Eoannou said. “We have an evidence bag that was ripped open — something was either taken out of it or placed in another bag.

“We’re hoping to get to the bottom of it. We’re hoping to find out how this happened and who had the incentive to modify or tamper with the evidence and finally get to the bottom of it rather than have misinformation about semen in one’s undergarments.”

Eoannou refused to speculate on who might have tampered with the evidence bag, indicating only that the chain of custody had been broken. In a statement released on Facebook, the Hamburg Police Department in New York wrote its “handling of the evidence and the integrity of its chain of custody of evidence in this case is unassailable.”

In response to Eoannou’s claim, Kane’s attorney Paul Cambria said, “This seems like an extremely unusual claim. I haven’t heard any facts that support it and the question I have is whether or not it’s a fabricated red herring.”

Kane, 26, hasn’t been charged in the sexual assault case as officials with the Hamburg police and the Erie County District Attorney’s Office continue to investigate the events surrounding the early morning hours of Aug. 2, when Kane returned to his Hamburg, N.Y., home with a friend, the alleged victim and one of her friends after a night out at the bar. The sexual assault is alleged to have occurred in Kane’s home after that.

Eoannou had no comment on whether he thought Kane would be charged, though he hopes the criminal case will move forward. Prior to Wednesday’s shocking revelation, a grand jury had been expected to be presented evidence in the coming weeks. It’s not clear how this development will affect that.

Evidence bags are typically stored at the lab, the police department or the district attorney’s office, Eoannou said. He wants state police or the FBI to look into how the evidence bag left the custody of investigators.

“In my 30-years plus of being a prosecutor and defense attorney, I have never seen an evidence bag outside of a police lab, the prosecutor’s office or courthouse,” Eoannou said. “Let only find one in the doorway of a rape victim’s mother’s home.”

The alleged victim has “always been determined” to have the truth come out and push forward with prosecuting Kane, Eoannou said.

The “victim bashing” has been “atrocious” for his client, Eoannou said.

“She is absolutely devastated,” he said. “This is a classic example of why rape victims don’t come forward in rape cases. This is the worst example of victim bashing I have seen.”

Kane’s only public comments directly pertaining to the case came last Thursday as the Blackhawks opened training camp at Notre Dame. He maintained his innocence.

“I’m confident that once all the facts are brought to light, I will be absolved of (wrongdoing),” Kane said.

Beyond that, Kane has added he doesn’t know of any timeline for a resolution and has only responded to hockey-related questions.

Kane played in the Blackhawks’ preseason opener Tuesday night at the United Center, a 5-4 win against the Red Wings. However, he didn’t accompany the team to Detroit for Wednesday night’s exhibition, the Associated Press reported.