Over the October long weekend, items including an old mattress complete with bedding, a car seat, unwanted toys and a pair of chairs were left strewn across the Montague Street site's lawn. 

Adding insult to injury, scavengers ripped open garbage bags full of clothing and threw the items everywhere. 

Dumping continues to be a "major problem" for the St Vincent de Paul Society, according to its website, which says unusable items have to be taken to the tip and disposed of at a "considerable expense".

Wollongong City Council addresses the issue in its Waste Wise Guide, advising people it is illegal to place any item outside a charity bin.

"Don't dump on a charity - make sure items are reusable, resaleable, clean, unsoiled and in working condition," it states. "It is illegal dumping to place any item outside a charity bin."