Bodies of two siblings found in Perth home

A man is being questioned after two siblings were found dead in a suspected double homicide at a Perth home on Easter Sunday.

The bodies of a man and a woman, believed to be aged in their 60s, were found inside a unit at an apartment block on Leonard Street in Victoria Park.

One of the victims lived in the unit, police confirmed.

Neighbour Colin Adams said he had heard screaming and yelling on Sunday afternoon.

"I'm very shocked and sad. It's just a numb feeling," he told reporters.

Police say a suspect, who also lives in the complex, was apprehended in the Perth CBD at about 9am on Monday and was assisting Homicide Squad detectives with their investigation.

"WA Police strongly believe that there is no further risk at a community level," Commander Allan Adams told reporters.

"Officers attended yesterday afternoon, and upon making sure that the apartment was sealed, they made a reasonably timely exit.

"It was subsequent broader forensic examination that identified the second deceased."

Forensic officers remain at the apartment, while two vehicles have been towed away.

Earlier, WA Police Commissioner Chris Dawson said he had a big team working on the case.

"It's clearly a very suspicious and tragic set of circumstances," he told ABC radio.

Anyone with information is asked to contact Crime Stoppers.