Property managers at high-end Auckland apartment buildings are going to desperate lengths to evict illegal brothels.

One said prostitutes were openly soliciting other residents, but she couldn't evict them until they fell behind with their rent.

Others have resorted to shaming clients and calling in police to "muscle out" prostitutes.

Property managers Jacqui Cheal and Larry Dickie, who manage about 80 central city apartments, said it took five months to remove a brothel from an expensive property in the Viaduct Harbour.

The tenant denied running the business, even though the brothel was advertised on a late-model Audi parked in the apartment's carpark.

"When we first confronted him to say we'd been told he was running a brothel he got quite aggressive and vicious," Cheal said. "He said 'You can't prove what's going on this apartment'."

The man, who paid $750 a week for the three-bedroom apartment, was rarely at the property. No one lived there full-time but three women worked from the premises during the day - breaking Auckland City Council rules for unlicensed brothels.

Cheal said the women told her most of their clients were corporate businessmen who visited during their lunchbreak.

The property managers complained to police and spoke three times to council officers. The council said two complaints were received and an investigation found no evidence of a brothel.

But Cheal said officers never contacted them to gain access to the apartment, and never reported back with the result of the investigation.

"We realised by then we weren't going to get any help."

The tenant was served notices for being in breach of the tenancy agreement by running a business, and acting in a way that could be offensive to other tenants. When the agreement was eventually terminated at a Tenancy Tribunal hearing, it was only on the basis of rent arrears.

"What do landlords and property managers do?" Cheal said. "It will get to the point where somebody will get hurt because they're trying to manhandle them out or evict them."

Cheal, who called for more power under the Residential Tenancy Act, said other property managers reported similar experiences, in one case shutting off power and water to force tenants out.

Another manager said it was common for brothels to set up in Viaduct Harbour apartments and he forced them out by making it known that clients would be identified and embarrassed.

"You just go and stand by the door and say to the people coming in, 'You realise ... you're on camera'. They won't come back."

A manager at another inner-city apartment complex relied on similar techniques to force out two prostitutes working from the property.

"In the end we were able to sort of muscle them out by getting the police involved because there was also drug offending," the manager said.

There are 16 licensed brothels in Auckland City. Small, owner-operated brothels don't need a licence if the operator lives on the premises, employs only one full-time equivalent person, and the business has no more impact on neighbours than a residential property.

The council's city development general manager John Duthie said 14 staff were available to investigate illegal brothels, but only received a couple of complaints a year.