The Papua New Guinea police commissioner, Anthony Wagambie, says he's furious an alleged sexual assault of a female detainee by a policeman, occurred at the Boroko Police Station in Port Moresby.
He says the matter will be thoroughly investigated.
The female detainee, an Australian citizen, was arrested last weekend during a murder investigation.
The metropolitan superintendent, Joseph Tondop, says no one is above the law and any officer who abuses his or her position will be severely dealt with.
He says commissioner Wagambie has declared the constabulary is no place for rogue policemen.