A female British military healthcare worker was evacuated from Sierra Leone after being accidentally pricked by a needle while treating Ebola patients.
She has returned to England for health monitoring and her next of kin have been informed, according to Public Health England (PHE).
The worker was flown back to RAF Brize Norton in Oxfordshire on Friday, and then taken to an isolation ward at the Royal Free Hospital in London.
It is believed that the person, whose identity remains anonymous, has probably been exposed to the virus but has not been diagnosed with Ebola and is currently not exhibiting any symptoms.
The official announcement stated that the worker suffered a "needle-stick injury" which suggests that the skin was pierced, according to Sky News.
"Our thoughts are with this person, who has been courageous in helping those affected in West Africa, and in preventing the wider spread of Ebola," said Paul Cosford, PHE director for health protection. "We have strict, well-tested protocols in place for this eventuality and we are confident that all appropriate actions have been taken to support the healthcare worker concerned and to protect the health of other people."
The needle-jab accident happened at the Kerry Town clinic in Sierra Leone. There are around 600 UK military personnel working in the country, with the Royal Fleet Auxiliary ship Argus moored nearby.
The clinic was built on the outskirts of the capital Freetown to help treat patients infected by the virus, which has ravaged parts of West Africa.
The Kerry Town clinic includes an 80-bed treatment centre managed by Save The Children charity and a 12-bed operated by British Army medical staff.
Sierra Leone is one of the worst-hit by the disease outbreak that has killed more than 8,600 people so far.
About 100 soldiers from the Royal Army Medical Corps were sent to the country in October as part of the British government's £330m effort to stop the spread of the virus.