Police have identified a suspect in a central Auckland apartment break-in and sexual assault last weekend that had investigators scouring CCTV footage and seeking the public's help.

The 32-year-old Castor Bay resident has been arrested and is set to appear in Auckland District Court today on charges of burglary, assault with intent to commit rape, indecent assault and three counts of doing an indecent act.

If convicted, he could face up to 10 years' prison.

In a press release yesterday asking for the public's help to identify the man, Detective Senior Sergeant Martin Friend said the woman was sexually assaulted in the communal area of an Albert St dwelling on Sunday night.

"Understandably the victim in this matter is incredibly shaken by what has happened and police are ensuring there are support services engaged for her," Friend said.

Police were able to trace the suspect's steps from a bus in Birkenhead starting at 6.50 that evening. Footage showed him getting off the bus in central Auckland about 20 minutes later and entering the woman's building around 9.20pm.

Image stills from the bus showed the mystery man wearing track pants and a jumper. But in another still taken as he was leaving the apartment, he appeared to be wearing a different top and no pants.

Police also appealed to the public yesterday to "practise good vigilance in ensuring entry doors close behind" when entering apartment buildings so that only authorised people are let in.