Siphathisiwe Ntuliki, a former work colleague of Grayson at the Royal Hallamshire Hospital, says she complained about him for what she felt was sexual harrassment and raised concerns over his use of cameras in 2012.
She says rather than being disciplined, he was promoted and she was bullied out of her job, for which she blames Grayson, saying he spread lies about her.
Grayson was jailed for 12 years last month after admitting offences committed at the hospital. He pleaded guilty to 14 charges of voyeurism, three sexual assaults, one charge of upskirting, one of taking indecent images of a child, one of installing recording equipment for the purposes of sexual gratification and three of possessing indecent images of children.
Ms Ntuliki, from Brightside said: “I reported him, and no one was listening. They missed an opportunity. I just feel sorry for his victims, because I felt it could have been prevented if they had listened to me 10 years ago. It has been painful to hear.
“In 2012 I experienced sexual harassment by Paul Grayson. I already had concerns about Paul Grayson's practice and felt that patients were not safe. I approached the clinical lead about three times to discuss this with her. No one was willing to do any investigation. I was thrown under the bus and he got promoted to a charge nurse.”
Ms Ntuliki worked at the Royal Hallamshire Hospital day case recovery unit from 2006 to 2014.
She said she was concerned Grayson was giving misleading information, and would phone other sections of the recovery unit to say he disagreed with certain orders or policies.
She said: “I also realised he was on his mobile phone a lot and brought a camera to work. He spent more time behind the curtains. I thought his standard of work was falling and patients were not safe.
“Then there was a time when he had no respect for patients and colleagues. I could hear him discussing about intimacy. I had a word with him and told him that was very wrong. I reported him to the management.
“Despite my repeated reports to the senior authorities no one was willing to do anything about it. But instead, he got promoted to a charge nurse.
“I was bullied and victimised until I resigned from work.”
The 53-year-old has now been asked to join an investigation team looking into how Grayson was able to do what he did.
Professor Chris Morley, Chief Nurse, Sheffield Teaching Hospitals, said: “Now that the criminal proceedings are complete, we have been able to begin a full review of what happened with regards to Paul Grayson and that includes asking current and past members of staff to share with us any information they may have to contribute.
“In the last two weeks we have received information from an ex-member of staff and we immediately responded inviting that individual to provide all the information they have. Although this was a very rare set of events and very much about one individual, the purpose of the review is to see if there are any further actions, we can take to limit the chances of something so awful ever happening again.”