The offence took place between 5.25am and 6.30am, in Hyde Park, a West Yorkshire Police spokesman said.
The victim had met a man in Vicar Lane, Leeds city centre, in the early hours before the pair took a taxi back to an unknown address in Hyde Park on August 18.
Now the force has today (Monday) released CCTV pictures of a man they want to speak to in connection with the offence.
Anyone with information is asked to call police Detective Constable Gemma Coulton, of Leeds District CID, via 101 and quote crime reference number 13180410544.
People can also call the independent charity Crimestoppers, anonymously, on 0800 555 111.