As Christmas draws closer postboxes around the city are being targeted.
There were reports of at least three mailboxes around Mandurah broken into yesterday, with shocking images making their way into community groups on Facebook.
A post made yesterday by Emily Murphy said she saw the letterbox at Greenfields shopping centre busted open as she went for a walk through nearby Bortolo Park.
Another Facebook user, Rebekah Ozanne, claims she saw a woman dressed in black with black hair and a white ute opening a post box near Halls Head.
Mrs Ozanne said around 9 o'clock on Tuesday morning she saw the woman at the oval on the corner of McLarty Road and Dalrymple Terrace in Halls Head, she also saw the post box at Farmer Jacks pried open.
The Halls Head resident said she did not report the matter because she assumed the women was working with Australia Post.
Mandurah Police say they're yet to receive any reports or information in relation to the matter, but anyone with CCTV footage or knowledge of the crimes should come forward and tell police.
Detective Walsh said it's likely thieves are looking for money or other valuables as Christmas draws closer.
Anyone with information in relation to this incident is asked to call Crime Stoppers on 1800 333 000 or to make a report online at www.crimestopperswa.com.au