Australia's Department of Health ordered a review into the handling of strawberries after fruit containing sewing needles was found in supermarkets across Australia.
More than 100 reports have been made of hidden needles, and two people who accidentally ate needles required treatment at a hospital.
Most are thought to be pranks or jokes on social media, but at least two minors have been questioned by police for carrying out hoaxes.
It comes as Prime Minister Scott Morrison announced on Thursday that anyone caught tampering with food will face tougher new criminal penalties, as part of a national response to the needle contamination crisis affecting Australia's strawberry growers.
His government has successfully raised the maximum prison sentence for fruit tampering from 10 to 15 years, with parliament passing the legislation on Thursday.
Last week, Australians were warned to cut fresh strawberries before biting into them after several people found sewing needles hidden inside the fruit.
Opposition leader Bill Shorten appeared in parliament to ask Australians to buy "a punnet for yourself and a punnet for the nation".
The boy, whose name has not been disclosed because of his age, confessed to putting the sewing needles in strawberries as a prank and is not believed to be the culprit behind other fruit contaminations in the region, New South Wales police authorities told ABC News. Now there are reports a needle was found inside a mango.
"We have worked with our suppliers to implement additional control measures to ensure strawberries are inspected before they are sent to supermarkets", a spokesperson said.
In NSW the maximum penalty for deliberately contaminating a food source is 10 years in jail.
"Stick it up these parasites by going into the supermarkets and buying strawberries", says Australia's Agriculture Minister David Littleproud.
A police source told AAP they were mindful of confirming specific cases for fear of inspiring more copycats.
The Queensland and Western Australian governments are offering similar rewards.
NSW Premier Gladys Berejiklian has promised to stand shoulder to shoulder with farmers.
'This is a disgusting act created to instil fear in consumers and to undermine our agricultural industry'.