WELLINGTON, March 13 -- A New Zealand health worker has been placed in isolation pending tests for the Ebola virus, Health Minister Jonathan Coleman said Friday.

The unidentified health worker had been part of New Zealand's contribution to the international response to the deadly virus in Sierra Leone, Coleman said in a statement.

The individual had left the West African country on Sunday and became unwell on Friday and reported to a public health officer.

"Based on the patient's symptoms, the Ebola virus needs to be ruled out," Coleman said in a statement.

"I am advised that it is quite possible they are suffering from gastroenteritis or some other illness such as malaria. Test results will be available in 24 to 48 hours."

"The only person who had direct contact with the patient during the potentially infectious period had been the patient's partner, who was also being monitored "according to internationally recognized protocols."

The patient was being transported from their home to Christchurch Hospital where they would be cared for in one of New Zealand's four speciality isolation facilities.

Blood samples would be sent to a high security reference laboratory in Australia for testing and it was expected to be 24 to 48 hours before a result was known.

"Ebola is not easy to catch, transmission requires direct contact with an infected individual and only occurs through contact with blood and other body fluids," said Coleman.

"People with Ebola are not infectious until they are displaying symptoms. If the health worker does have Ebola, they will not have been infectious while traveling as the individual was not symptomatic at that time."

New Zealand was well placed to handle and respond to cases of suspected Ebola and the eventuality had been very carefully planned for, he said.