The incident happened at around 5am on Sunday 29 July 2018 when a woman in her 30s was assaulted in an alleyway close to the car park off Havelock Square and Havelock Street.
We issued the CCTV image at the time, but unfortunately have not managed to identify the man pictured.
Our enquiries have continued and we are now re-issuing the photograph in the hope that someone recognises him and comes forward to police.
Det Con Rachel Catling, from Swindon CID, said: “We have carried out an extensive investigation over the past six months but have not yet managed to find out who the man in the picture is.
“We believe he spoke with an Irish accent, and our enquiries have suggested that he may either currently live in the Republic of Ireland, or have lived there at some point.
“These are clear CCTV images so we believe someone out there will recognises him and provide vital information to assist with our investigation.
“This assault has been understandably traumatic for the victim and we have continued to provide her with ongoing support.
“If you are the man in the picture, or you know who he is, please come forward and speak to us.”
Anyone with information should contact DC Catling from Wiltshire Police on 101, quoting crime reference 54180070838.
Alternatively you can call Crimestoppers anonymously on 0800 555111.
If you are calling from abroad, then please dial 01380 826614.