A New Zealand nurse who recently returned from Sierra Leone has been officially cleared of the Ebola virus.

The nurse, who is in a stable condition in Christchurch Hospital, has tested negative for the deadly disease twice, and her partner has also been cleared to return to work.

Health Minister Dr Jonathan Coleman said it was “great news” that the second negative test had now returned.

“In line with international protocols, a second test was required to rule out Ebola,” he said in a statement.

Dr Coleman thanked Melbourne’s Victorian Infectious Disease Reference Laboratory for quickly turning around the test results.

“Their prompt work is much appreciated,” he said.

“This case has proven that New Zealand’s well-practised procedures worked extremely well. It is a credit to all the health staff who were involved.”

The nurse returned from working in West Africa, as part of New Zealand’s contribution to the international response to Ebola, on March 8, and developed gastroenteritis symptoms on March 13, when she reported to the local Public Health Officer as part of the daily self-monitoring process.

The nurse was conveyed from her Christchurch home to hospital via helicopter and was transported in a specialist Iso-pod patient transfer unit.

The patient was then treated in a dedicated specialist medical isolation room at Christchurch Hospital while the tests were carried out.

Dr Coleman previously stated the nurse and her family had carefully followed protocols for returning health workers in a bid to ensure there was no potential risk of others being exposed to the virus.

“I would also like to recognise the collective efforts of the many health workers involved, including St John’s Ambulance, Southern Regional Public Health, Canterbury DHB, and the Ministry of Health.

“The health sector has planned for months for just such an eventuality, and it is pleasing to see that all the preparation has paid off.”

The nurse’s Ebola clearance comes after a doctor working at the Australian-managed Ebola Treatment Centre (ETC) in Sierra Leone began a 21-day observation period for the virus in the United Kingdom after a “clinical incident”.

Foreign Affairs Minister Julie Bishop said a full investigation into the incident is now underway.

Ms Bishop said the doctor, who has completed a medical assessment in the UK, has not been diagnosed with Ebola and is not exhibiting any symptoms of the virus.

Almost 120 patients have been discharged from the ETC, with 36 patients recovering from Ebola.

Aspen Medical has received about 1000 applications from doctors, nurses and allied health professionals wanting to assist at the Australian-flagged ETC, including more than 100 from New Zealand health care professionals.

The World Health Organisation reports there has been more than 24,000 confirmed, probable and suspected cases of Ebola in Guinea, Liberia and Sierra Leone with almost 10,000 reported deaths, since the start of the outbreak.

There has been 840 confirmed health workers infected in those three intense-transmission countries, including 491 deaths.