Security has been stepped up at Royal Liverpool Hospital after the woman was sexually assaulted in its NCP multi-storey car park on Sunday, September 18.
Merseyside Police says officers believe the attack happened between 10.30am and 1pm and the offender was a complete stranger.
The force says it is ‘carrying out extensive enquiries’ and the woman is being supported by specially trained officers after the shocking incident.
Detective Inspector at Merseyside Police, Paul McVeigh, said: ‘Incidents of this nature are very rare and while I understand that members of the public may be alarmed I want people to be reassured that we are carrying out a full and thorough investigation to establish what has taken place and apprehend the person responsible.
‘I would like to appeal to anyone who was in the area of Mount Vernon Street on the morning of Sunday September 18, who saw or heard anything suspicious, or thinks they may have captured something on their vehicle dash-cam to contact us as a matter or urgency.
‘We are carrying out extensive enquiries in the area including obtaining CCTV footage. If anyone witnessed the incident or has any information that can help with our enquiries please get in touch.
‘Violence against women and girls in any form is not acceptable and Merseyside Police has a number of initiatives in place to ensure the response to crimes of this nature are prioritised and that the appropriate policing activity is put in place to address the safety of women and girls.
‘Providing support to victims of sexual assault has also never been more important. If anyone who has suffered a sexual offence can find the courage to come forward and speak to us, I want to assure them we will deal with them sensitively and make sure that reports are thoroughly investigated.’
David Melia, Chief Nurse at Liverpool University Hospitals NHS Foundation Trust, said: ‘The Trust is assisting Merseyside Police with their inquiries into an incident that was alleged to have taken place on the grounds of the Royal Liverpool University Hospital on 18 September.
‘As an extra precaution 24 hour security around the site has been increased.’
Anyone who witnessed the incident or who has information is asked to DM @MerPolCC, message ‘Merseyside Police Contact Centre on Facebook’ or contact @CrimestoppersUK on 0800 555 111 with reference 22000696768.