Queensland Police Commissioner Ian Stewart said police had received one report of a metal object in a banana but it is understood the incident was isolated and involved a person placing a metal object in a banana at a shop.

"There are significant leads in relation to that [banana] matter," he said.

A 62-year-old woman is assisting Maryborough Police over the alleged incident reported at a supermarket in the town.

Mr Stewart said the potential for copycat events was "very real" and the strawberry investigation was ongoing.

"We're focusing very, very much on the supply chain, the people involved in that, this is a very, very significant, economically powerful industry, particularly in the south-east of Queensland and obviously of great concern," he said.

One Queensland grower planned to purchase a metal detector to prove the fruit leaving his Glasshouse Mountain farm is safe.

The farmer, Leonard Smith, said the safety measure would cost him about $30,000, but would hopefully get the rest of this season's fruit back on supermarket shelves.

Mr Stewart said there had been incidents across Australia and Queensland police were working with counterparts interstate.

"There's some specific leads that we're following in relation to the banana incident - strawberries are still our major focus," he said.

Agriculture Minister Mark Furner was meeting with the Queensland Strawberry Growers Association on Monday afternoon.

Premier Annastacia Palaszczuk said she wanted to talk to the association and federal government before considering any relief package for the strawberry industry.

"It is unbelievable that any person could do this knowing the eventual harm or destruction it could do to a human life," she said.

Queensland chief health officer Dr Jeanette Young said on Monday that there had been no further reports of needles or metal objects found in strawberries in Queensland, and only three brands had been withdrawn from the market.

The state government has offered a $100,000 reward for any information leading to the arrest and conviction of anyone responsible for the strawberry sabotage.

Berry Licious, Berry Obsession and Donnybrook branded strawberries, all Queensland brands, remain off the shelves at some supermarkets with Coles pulling all strawberries off their shelves except in Western Australia.

New Zealand company Foodstuffs has halted all imports of Australian strawberries after needles were discovered in strawberries sold in Queensland, Victoria and NSW.

Federal Health Minister Greg Hunt has also ordered the national food safety watchdog to assess Queensland's handling of strawberry contamination.

"This is a very vicious crime and it's a general attack on the public, and it's also an attack on a specific industry," he told reporters on Sunday.

But in a sign of returning confidence, on Monday Aldi supermarkets announced that strawberries would be returned to their shelves.

"Following information provided by the Queensland State Health Emergency Co-ordination Centre and the state-based Food Safety Authorities, Aldi has decided to return a selection of strawberries back to shelves as soon as the orders can be fulfilled and distributed," Aldi said in a statement.

Dr Young urged people to continue purchasing and consuming strawberries, but to cut them up before eating them.

- with AAP