Several brands grown in Queensland have been withdrawn from supermarkets, and there have been multiple reports of other cases in the states of New South Wales and Victoria.
Queensland mother Angela Stevenson said her nine-year-old son Mason bit into a strawberry with a needle in it, and she found another metal object while cutting up a piece of the fruit to feed to her 12-month-old baby Koby-Rose.
Certain brands have been removed from sale.
ABC News reported on Saturday that wholesale prices have halved to 50 Australian cents per punnet below the cost of production in Western Australia, where strawberries crops are now peaking, with growers forced to dump tonnes of the fruit.
The Queensland Strawberry Growers Association described the incident as "extremely disheartening and troubling".
Sewing needles were initially found in punnets of the fruit in Queensland last week, but the problem has since spread.
It was pretty serious for some people as one man had to be taken to hospital for emergency medical attention after swallowing part of a needle.More news: Duke Energy shutting down North Carolina nuke plant ahead of Florence
More news: NASA releases footage showing massive Hurricane Florence from space
More news: Sarri Concedes Chelsea Not Title Contenders This Season
The Department of Health is advising Australians to cut fruit prior to eating, in light of recent events.
"This is putting families' lives at risk and it's also putting the strawberry industry at risk ..."
Initially, it was thought just Berry Licious and Berry Obsession strawberries were affected, after Queensland Police and Queensland Health warned members of the public on Wednesday.
Adrian Schultz, from the Queensland Strawberry Growers Association, said the sabotage may have begun with a single "act of commercial terrorism" but was threatening a multi-million-dollar industry.
"We're focusing very, very much on supply chain, the people involved in that", Mr Stewart said.
Authorities in Queensland, where the first contamination case occurred, have offered a $100,000 reward. At the end of the day strawberries don't grow needles, someone's physically (putting them in). "It is a very, very broad picture and we can't speculate in any way, shape or form", said Terry Lawrence, Queensland acting chief superintendent.