Strict export rules have been introduced as Australia’s national needle contamination scare leaves strawberry growers in crisis and police baffled.

Exporters have been told they must prove their fruit has been cleared through a metal detector or x-ray machine before the federal Department of Agriculture will issue a permit

Queensland Strawberry Industry Officer Jennifer Rowlings said some trade partners in Russia and the UK have already blocked Australian imports, while New Zealand announced this week it would pull Australian-grown berries from its supermarket shelves.

All six states have received reports of sewing needles and other metal spikes in berries since Queensland police announced their investigation into the sabotage almost two weeks ago.

There have also been reports of apples and bananas being targeted with needles as police fear a spate of copy cats.

New South Wales police are investigating at least 20 cases of needles being found in fruit, and has warned perpetrators – including copycat perpetrators and consumers falsely claiming a discovery – could face up to 10 years in jail for food contamination.

Detective Superintendent Danny Doherty, from the robberies and serious crimes unit, said it was “fortuitous” there hadn’t been any significant injuries yet. Contamination incidents were occurring across the state, including in a northern NSW school.

“The motive appears unclear, I mean who puts needles in strawberries knowing it goes to kids and families?”

The comments from Doherty came after Seven News reported a woman in Kellyville Ridge said she found a needle in an apple she bought from a Woolworths supermarket on Tuesday.

In an image published by Seven News, the green apple has been entirely peeled, and a sewing needle is shown sticking up out of the side.

A needle has been found inside an apple and police are now investigating. #Apples #7News pic.twitter.com/TRt3I3YlC3 — 7 News Sydney (@7NewsSydney) September 18, 2018

A Woolworths spokesman said “we’re looking into this”.

Doherty said it was hard to tell how many cases after the original incidents in Queensland were copycat or self-contamination, but he said the effect was the same – alarm for the public and economic loss for the industry.

Cases of self-contamination would also be treated as food contamination which was “a serious offence” and can carry 10 years’ jail, he said.

Customers were still warned to cut up fruit.

“The consequences are dire, it’s a hazardous action that’s happening by whoever’s perpetrating it. Really at the end of the day it’s an act of treachery to the people of Australia and across the country.”

The Queensland and WA governments have offered a $100,000 reward for information leading to convictions.

On Tuesday, police said they had received reports of needles being discovered with strawberries in the Perth suburbs of Kelmscott, Spearwood and Bull Creek.

Strawberry Association WA vice president Paul Da Silva said the contamination was definitely not happening at farm level and it looked like “copy cats”.

The contamination scare began with strawberries, but now includes at least one apple and a banana in NSW.

On Monday a 62-year-old woman was also caught sticking a needle into a banana in a shop in Mackay, in an apparent copycat act.

The woman, who is understood to have mental health issues, was given a warning and referred to appropriate support services.

“The community is reminded that contaminating food is treated as a serious offence and a threat to public safety,” a police spokesperson said. “All reported incidents will be investigated thoroughly.”

Queensland Police told Guardian Australia on Monday copycat incidents were “a concern that police are aware of”.

“They appear to be more likely consumers, but police have an open mind”.

Needles have been found in strawberries in all six states of the country, prompting recalls and warnings to discard the fruit.

“The sabotage of our strawberry industry is not just an attack on hard-working growers and workers but it reaches into almost every home and school lunchbox,” said Queensland premier, Annastacia Palaszczuk, whose government will spend $1m to look at ways to boost integrity in the supply chain and help growers through the rest of the season.

“The community needs to come together and help police catch those responsible and restore our industry to the place of pride it deserves.”

Megan Sherry, whose family owns a South Australian strawberry farm, said they were “terrified” about the impact of the scandal.

The farm produces an interstate brand, Kuitpo Forest strawberries, and a local brand, Harvest the Fleurieu.

“We’ve had very promising comments come through [from the local market] - almost every customer has said something about it,” she said.

“We’re a bit more worried about the interstate.”

The needle contamination crisis has forced strawberry farmers to begin dumping tonnes of the fruit. Video credit: Stephanie Chheang. Report on 7 News at 6pm. #7News pic.twitter.com/AsdGrB6CGw — 7 News Brisbane (@7NewsBrisbane) September 18, 2018

Sherry said the business was reevaluating when to start their season - harvest can be pushed slightly - in the hope this would blow over.

“The market has been low for the last three years so we needed a good start to the season. This kind of scandal is going to kill us.”

Like other growers, they would be installing a metal detector, which Sherry said was just “an added expense for an already struggling market.”

“When it leaves our farm it definitely doesn’t have anything needles in it.”

However she noted that a Queensland farm whose strawberries were implicated in the Tasmanian needly discovery already have a metal detector, making it unlikely the contamination occurred on site.

Glass House Mountains farmer Leonard Smith said he was forced to burn off 500,000 unsellable plants on the weekend because it was cheaper to destroy them than pick them.

One farmer from the Atherton Tablelands said he had to lay off 15 employees while his business tried to bounce back. But he said locals in the region were rallying to help farmers by buying fruit at the farm gate.

Queensland’s 150 strawberry farmers produce 60 million punnets of the fruit a year, worth $160m.

The Queensland Strawberry Growers Association vice-president, Adrian Schultz, said “commercial terrorism” had brought the industry to its knees.