SYDNEY - Australian authorities said on Sunday they were checking whether rockmelons had been exported from a farm where fruit contaminated with listeria has been found to have killed three elderly people and caused illness in at least 12 others.

New South Wales Food Authority said that the company whose rockmelons, also called cantaloupes, had been contaminated with listeria, is an exporter of produce. The Department of Agriculture and Water Resources said that it was investigating whether any rockmelons had been exported.

"Australia will be issuing notifications in line with international obligations when affected countries are identified," the department said in an email.

It declined to name possible export destinations, or if any had been recalled, while the investigation was underway.

Australian rockmelons with an export value of about $20 million per year go to Singapore, Hong Kong, New Zealand, the United Arab Emirates and Brunei, the Australian Melon Industry said on its website.

The suspect cantaloupes were found to have been farmed at Nericon in the eastern state of New South Wales, however all government departments contacted refused to name the company that is the focus of the health scare.

But, Dianne Fullelove, industry development manager for the Australian Melon Association, told Reuters by text message that the grower had issued a trade-level recall, meaning that its produce should not be on sale anywhere, either inside or outside the country.

"There is none of the produce from the implicated farm now in domestic or export markets," she said.

State health officials have confirmed they began investigating the listeria outbreak on February 19.

Listeriosis does not cause illness in many people but it can result in serious sickness and death in those with weakened immune systems.

Removed

Health authorities assured the public that all contaminated rockmelons were removed from Australian supermarket shelves.

Listeriosis symptoms can take up to six weeks to appear. The flu-like symptoms can lead to nausea, diarrhea and infection of the blood stream and brain.

The bacteria is found in soil, water and vegetation and can contaminate food anywhere during the production process from harvesting to serving.

Foods that can pose a risk of listeriosis include pre-cut melons, cold salads, raw seafood and smoked salmon, unpasteurized milk products, sprouted seeds and raw mushrooms.

Reuters