Homicide detectives have charged a 27-year-old man with two counts of murder after a woman and her brother were found dead in an apartment in the Perth suburb of Victoria Park.

The bodies of Maree Collins, 66, and her 62-year-old brother Wayne Johnson were found in a unit late on Sunday.

The man, who was a neighbour of one of the victims, was arrested in the Perth CBD the following morning after a 17-hour manhunt.

Forensic investigators remained at the eight-storey Leonard Street building during the week where a large crime scene was established on the top floor.

Police set up a crime scene at the apartment block to gather evidence in their investigation. Photo: ABC News/James Carmody

Neighbours described hearing screaming and yelling about 4:00pm on Sunday afternoon, before more than a dozen police cars arrived along with two ambulances.

Police said one of the bodies was discovered in the apartment a number of hours after the first body was found.

Information given to police on Monday morning led to the accused man’s arrest about 9:00am in the city, just a few kilometres from the crime scene.

Forensic police could be seen on the balcony of the apartment block as they searched for clues. Photo: ABC News/James Carmody

The Victoria Park man is due to face Perth Magistrates Court later today.

-ABC