Not all berries being checked

Not all imported frozen berries are being checked by Australian authorities despite concerns of a broader hepatitis A outbreak.

Only berries linked to the processor at the centre of the controversy, Patties Foods, are subject to inspection and testing.

A second processor in NSW has been ordered to hold back its imports from distribution.

The revelation about checks came on Monday after the head of the agriculture department appeared to contradict Prime Minister Tony Abbott's promises of more rigorous testing of imported frozen berries.

Mr Abbott last week said there would now be 100 per cent screening of "these sorts of imports" in response to concerns.

That did not align with what department secretary Paul Grimes told a Senate estimates hearing on Monday.

"We have not made changes on surveillance rates for berries broadly at this stage," he said.

Mr Abbott clarified later there would be greater surveillance only of the "relevant" frozen berries - those linked to Patties.

"There is no inconsistency with what has been said," he told parliament.

Eighteen people have so far been diagnosed with hepatitis A linked to imported frozen berries, a week after a nationwide recall was issued for a range of products.

The department first heard about contamination concerns on February 13, after which it alerted the industry, importers and the Chinese government on various protocols.

China has launched an investigation into Australia's contamination concerns, but it may be delayed because of New Year celebrations, department officials told the hearing.

The department is also preventing suspect mixed berries and raspberries from two factories from being sold in supermarkets, under holding orders that expire on June 1.

One importer in NSW who sourced suspect raspberries from the same Chinese factory as Patties was alerted last Thursday and ordered to hold them.

There are no plans to increase staffing to deal with imported frozen berries.

The division responsible for inspecting food risks shed 280 full-time jobs last year following a department restructure.

"The sorts of actions the department will be taking now are not on staffing, they are actually about what powers are available to it under (law)," deputy secretary Rona Mellor said.

Only a small number - five per cent - of all non-suspect imported berries are being tested.

"Isn't this ringing alarm bells?" Greens senator Rachel Siewert asked.

Officials said there was no evidence of other contaminated berries coming into the country, and the two factories under scrutiny had temporarily halted production.