The federal government will increase from 10 to 15 years the maximum prison sentence for food tampering offences. The new laws will be drafted rapidly and introduced to Parliament this week.

The Prime Minister's intervention came as the strawberry industry confirmed that major Victorian growers would use metal detecting equipment as they processed the crop this coming harvest.

Victoria is the nation’s second biggest strawberry producing state behind Queensland and produced 32,790 tonnes of strawberries in 2016-17, or about 36 per cent of that year’s crop. Picking in Victoria commences in about mid-October and growers are concerned about the possible impact on their businesses of the bizarre strawberry sabotage crisis that has hit Queensland growers.

The crisis began on September 9, after a Queensland man ate a strawberry with a sewing needle inside. In the weeks since there have been more than 100 reports of contaminated fruit affecting strawberries and other fruit, six strawberry brands have been recalled nationally and the Queensland government approved a $100,000 reward for information leading to an arrest.

"It is important to send a very clear message to ensure that we have the right penalties and have the right offences that are in place to ensure that we protect against these sorts of things into the future," Mr Morrison said.

New offences linked to "reckless" conduct, including hoaxes and social media posts showing fruit being tampered with, will attract penalties of up to 10 years imprisonment.

"It's not a joke, it's not funny, you are putting the livelihoods of hard working Australians at risk. And you are scaring children," Mr Morrison said.

"If you do that sort of thing in this country we will come after you and we will throw the book at you. You are a coward and a grub."

Home Affairs Minister Peter Dutton revealed there are now more than 100 reports of contaminated fruit.

"We believe a lot of these will be hoaxes or copycat events, but the most important point is it's a diversion of resources, policing resources, when we want to find the true culprits," he said.

Mr Morrison also announced $1 million in federal funding to assist the response to the crisis.

The new laws will not apply retrospectively, meaning that previous examples of tampering will not face the more severe penalties. The government wants the changes legislated by the end of the week.

Victorian strawberry grower John Calle, chairman of Strawberries Australia and president of the Victorian Strawberry Growers Association, urged supermarkets to keep stocking strawberries.

“The strawberries are safe to eat...wash them and cut them and eat them,” he said.

Asked if the Queensland crisis was hurting the Victorian industry, he said: “At this point in time it hasn’t had any impact on us, but we’re worried that it might have an impact. The sooner we can get strawberries up on the shelf and start promoting the rest of the strawberries that are around from Queensland and Western Australia, the better it is for the industry as a whole, not just Victoria.”

Mr Calle said major Victorian growers were installing metal detecting equipment to test their strawberries during the coming harvest.

“Some of them did because otherwise the supermarkets would not have them on the shelves. So it’s another cost,” he said.

Asked about the mood among Victorian growers ahead of the harvest, Mr Calle said: “They are worried that this is going to impact us when we start, that people are not going to buy strawberries.”

Shortly after Mr Morrison announced the tougher penalties, NSW Police announced a $100,000 reward for information leading to the prosecution of any individual who contaminates a food source.

Police say there have been over 20 incidents of contamination in NSW since September 12, but Stuart Smith, Acting Commander, State Crime Command said police believe it's the work of copycats and pranksters, and not connected with the initial strawberry contamination in Queensland.

"In the last two 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," acting Commander Smith said.

Acting Commander Smith said it makes no difference to the seriousness of the crime or the punishment, whether it's a copycat crime or not.

"The offence is very clear, whether it's done with the intention of prank, whether it's done with the intention of serious harm to another individual, it's no different. They're going to be charged with that offence and they're going to appear before a court."