The Australian Department of Agriculture, Fisheries and Forestry confirmed on Thursday it was aware the ban may be enacted "pending further investigation".

"The department is awaiting official correspondence from Indonesia to confirm this," it said in a statement.

On Tuesday, the department confirmed several cattle had died on the Brahman Express over the weekend but would not confirm the exact number.

The cattle were inspected as required under the Export Control Act before leaving Darwin on March 14.

The ship arrived in Indonesia on March 20.

Investigations are ongoing into the cause of the livestock death but early signs point to botulism - a rare poisoning that attacks the nervous system.

"It is not a contagious or exotic disease and is not a risk to the Australian herd or to human health," the department said.

Botulism in cattle is often caused by the cattle eating a toxin produced by bacteria in contaminated feed.

The department said botulism was difficult to test for and would be a process of elimination which could take some time.

Testing undertaken at the Northern Territory government's Berrimah Veterinary Laboratory has excluded Bovine Ephemeral Fever and tick fever as possible causes of mortality.

"Australia is confident there is no evidence of an exotic disease and our animal health status remains unchanged," the department said.

Australian Associated Press