A victim came forward to police earlier this year alleging they were sexually assaulted at student accommodation at a hospital in Ealing, west London, in late 1977 or early 1978.
So far, officers have been unable to fully identify the man in the photograph, although his first name is thought to be Gary.
The picture that has been released is from the late 1970s and detectives have called on anyone who can identify the man to get in touch.
Police are appealing for anyone who can identify the man in the picture to get in touch (Metropolitan Police/PA)
A statement from the Metropolitan Police said: “Despite extensive inquiries being undertaken, the man, who officers believe may be called Gary, remains unidentified.
“The image released is from the late 1970s, but we are hoping that someone who recognises the man can tell us who and where he is.
“If the man in the image is you, please contact police immediately.”
Anyone with information can call police on 101 quoting the reference CAD 4971/08SEP2023, or to remain anonymous contact Crimestoppers on 0800 555111 or online.