Police are trying to find a man who took a bus to the Auckland CBD and then sexually assaulted a woman in a residential complex.
The incident occurred last Sunday night in the communal area of a residential block in Albert Street.
Detective Senior Sergeant Martin Friend, of the Auckland City CIB, said the woman had been left "incredibly shaken" and had been offered support services.
Police believed the alleged offender boarded a bus, route 95B, at 6.50pm on Onewa Road in Birkenhead and got off at Britomart at 7.08pm.
Just over two hours later he went into the residential complex, assaulted the woman and then left on foot.
Friend said the priority was to identify the man and police were appealing to the public for information.
"[Some members of] The public may have seen the offender moving around the city immediately after the incident and we would ask them to contact police if they have not already spoken to us.
"Residents in the central city will no doubt be concerned by this incident and we would like to reassure them that this matter is being taken extremely seriously."
Friend said people going into or out of buildings should be vigilant about other people tail-gating them to gain unauthorised access.
Any suspicious activity should be reported by phoning 111.
Anyone with information is asked to contact police via 105, quoting file number 220724/6978.