Over the Easter weekend, items including an old lounge suite, a discarded desk chair and unwanted children's toys were left strewn across the Montague Street site's lawn.

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."