Police investigating an alleged sex attack on a 90-year-old woman want to speak to a man who was seen in the area at the time.
They believe he could have valuable investigation that could assist their inquiries.
The pensioner told officers she was dragged off the street and raped while on a trip to her local butcher's shop in Rochdale at about 6.45am on Tuesday, but later forensic tests showed no evidence that could corroborate her allegation.
A man was seen walking along Spotland Road past the doctor's surgery at about 6.50am.
He is described as white, of medium height and build, with short collar length brown/black hair.
He was wearing a dark denim jacket and light denim jeans, black footwear and he was clean shaven.
Superintendent Alistair Mallen said: "We have spoken to a witness who has described seeing this man in the area - on Spotland Road near to the junction with Sheriff Street - round about the time of the incident.
We believe this man could hold vital information that could help us piece together exactly what happened on Tuesday morning so it is really important that he gets in touch.
"At this stage we cannot say what this man may have seen, or even whether he was in some way involved. Either way, he could be a key witness to this investigation.
"We would also like to hear from anyone who was in the area who we haven't yet spoken to.
"We have had an overwhelming response from the public and the media since we publicised this case and that support continues.
However, we are continuing to investigate the full circumstances of what happened to her. Something has clearly happened to this lady so we would like to hear from anyone who saw anything."
Specially-trained officers are continuing to work with the pensioner and offer her support, police added.
Police investigating an attack on a 90-year-old woman in Rochdale have fast-tracked forensic tests and found there is no forensic evidence to confirm that an attack of a sexual nature took place.
Specially-trained officers are continuing to work with the 90-year-old lady and offer her support.
Superintendent Alistair Mallen based at Rochdale, said: "We have had an overwhelming response from the public and the media since we publicised this case yesterday and for that we are extremely grateful.
"This demonstrates once again the great sense of community that continues in Rochdale and across the country.
"The lady in question stated she had been raped and she gave the same account when she was video interviewed.
"As people would expect we carried out forensic tests and these were fast-tracked overnight. At this stage no forensic evidence has been obtained.
"However, we are continuing to investigate the full circumstances of what happened to her. Something has clearly happened to this lady so we would like to hear from anyone who saw anything.
"It is important to state that was a report made in good faith, by an elderly, vulnerable lady and, as such, people would always expect us to investigate thoroughly.
"When we receive a report of this nature we will always investigate to establish the full facts and, alongside this, we will do everything we can to support the victim.
"People may question why we took the decision to go public and, to that, I can say that we had a duty of care to both the complainant and to the wider public. When making these decisions we have to weigh up the need to inform the public with the need to reassure them that they are not in any danger.
"Every case is considered on its individual merits at that particular time and, in this case, it was felt the community needed to be made aware.
"The most important aspect to remember is that we will always investigate reports of sexual offences and we always encourage victims to speak to the police.
"We are continuing to appeal to anyone who may have seen this lady to help us piece together exactly what happened."
An investigating officer said the woman was walking along Spotland Road when she felt a hand go over her mouth and was dragged backwards. She lost then consciousness and awoke on the floor after the attack.
The victim then managed to walk to the butchers and call police.
Police now want to hear from anyone who may have seen the victim, and potentially the offender, on the morning of the attack. She is white and wore a white summer dress with a flower print and a cardigan. The only description of the offender is that he was white.
Superintendent Alistair Mallen said: “I am sure the entire community will share our revulsion at this.
“The victim has been through an horrific ordeal and we are all hoping she can make a full recovery.
“She is now being supported by experienced officers and we are doing everything possible to reassure her that we will catch the man responsible.
“This kind of attack is thankfully so rare that it will naturally cause a huge amount of concern in the community.
“I now want people, including the criminal fraternity, to imagine if that had been your mum or grandma. I want to harness these feelings and use them to help the police do their job - catch this man and put him before the courts.
“So, this happened in a busy part of town at the start of a normal working day. Did you see the lady walking down Spotland Road before 7am yesterday and, if so, did you see anyone else nearby.
“It may not have struck you as significant at the time, but please, if you saw anything or anyone that you think could be relevant then please call the police.