The victim, a vulnerable man in his 40s, was attacked in a car park just off Manchester Road in the early hours of Saturday 5 September.
His attacker is described as a white man in his 20s with short brown hair.
A 35-year-old man was previously arrested in connection with the rape, but later released without charge.
Greater Manchester Police have now released a second tranche of CCTV footage and urged witnesses to contact them.
Det Insp Damian Simpson said: "It is a month since this terrifying attack took place and, despite our extensive enquiries, we are still looking for the person responsible.
"We have released this new footage in the hope that somebody will recognise the man or at the very least it may jog someone's memory."
Police investigating the rape of a man in Bolton have released further CCTV footage of a suspect they are looking for.