Needles have been found in more than 20 punnets of strawberries across NSW and potentially 100 pieces of fruit across the nation in the week since the sabotage was first detected in Queensland.
NSW Police on Wednesday announced a $100,000 reward for information that leads to a conviction for contaminated fruit.
One young boy has already been arrested over behaviour that "could be called a prank", acting police assistant commissioner Stuart Smith said.
“Obviously in the last few days we found a young person has admitted to a prank, including putting needles in strawberries, and he’ll be dealt with under the youth cautioning system."
A nine-year-old Tasmanian boy has found a metal pin inside an apple, according to reports on Thursday morning.
Police were told of the alleged contamination incident on Wednesday afternoon, after the boy discovered the pin while eating a Royal Gala apple bought from Huonville Woolworths on Monday.
The pin has been seized by detectives who say they are co-operating with other jurisdictions in investigating the incident.
Meanwhile reports emerged on Wednesday evening of another contaminated banana in Newcastle.
A police source told AAP they were mindful of confirming specific cases for fear of inspiring more copycats.
Agriculture Minister David Littleproud says the "parasites" responsible for spiking strawberries should "swing for this" and do hard time.
The government is rushing legislation through parliament to ratchet up the maximum penalties for so-called "food terrorists" from 10 to 15 years behind bars.
Prime Minister Scott Morrison wants the tough sanctions approved before federal politicians depart Canberra on Thursday.
"I'm just focused on making sure no idiot goes into a supermarket this weekend and does something ridiculous," Mr Morrison told reporters in Royalla in NSW.
"We've booked the hall in parliament for the day, we've paid the rent on it, and that means no one goes home until those bills are passed."
Labor's shadow cabinet will meet on Thursday morning to consider the legislation.
More than 100 reports of tampered fruit are being investigated by police across the country, many of which are thought to be fake or copycat cases.
Anyone who tampers with food could soon face up to 15 years' jail, in line with child pornography and terror financing offences.
There will also be a new offence of being reckless in causing harm, which will carry a maximum penalty of 10 years in prison.
The most serious cases with national security implications will be covered by sabotage offences, with penalties ranging from seven to 25 years' jail.
"The reality is that they should swing for this, they've got to do some time," Mr Littleproud told ABC radio.
"The one thing that people can do better than government is go and buy strawberries. Stick it up these parasites by going into the supermarkets and buying strawberries."
The agriculture minister has not received a full briefing from police as to where their investigations are at.
The Queensland and NSW governments are offering a reward to catch the culprits.
The government is also providing $1 million to make more food safety officials available to increase detection, fast-track recalls and assist the industry to rebuild confidence.
