Australian health officials have urged tourists who visited a popular adventure ranch west of the Great Barrier Reef at the weekend to come forward after a horse died from the killer Hendra virus.

Passed from fruit bats (flying foxes) to horses and highly fatal to humans, Hendra claimed the life of a horse at the Blazing Saddles adventure farm on Monday, west of the Reef gateway city Cairns.

At least six people were known to have had contact with the sick animal and Queensland health officials said they were working to determine how many others could have been exposed at the popular tourist site.

“I would like to reassure any tourists or visitors to the property over the weekend that transmission of the virus requires close contact with body fluids of the sick horse,” said Queensland health chief Jeannette Young.

“Queensland Health staff will continue to undertake contact tracing work to ensure all people potentially exposed to the sick horse have been identified.”

Anyone who had visited the ranch since last Thursday and had concerns were urged to call the public health hotline, she said.

“Queensland Health stands ready to provide any assistance, counselling, information, testing or treatment that may be required,” added Ms Young.