A shift in UK government policy due to the Ebola outbreak means African airline Gambia Bird has been forced to suspend services between London and West Africa, security firm Westminster said.
The airline had received the necessary permissions to operate the route again from the UK Civil Aviation Authority (CAA) and had fully intended to restart service as of October 17.
However, these permissions have now been withdrawn.
The airline said it would appeal the decision, especially as its licence was only granted on September 26.
Gambia Bird's official agent in the UK, McPhillips Travel, said the decision was disappointing, cosidering the route would provide far easier, cost-effective access for humanitarian assistance to Sierra Leone in the form of Non-Governmental Organisation (NGO) volunteers, medical professionals and supplies to combat the Ebola epidemic.
"It would allow UK based businesses and workers who are still trying to access the country and contribute to boosting its badly damaged economy a reliable means of doing so.
"Gambia Bird had put in place extremely stringent health and safety procedures to protect both passengers and crew, combined with thorough checks of passengers at Lungi International Airport prior to exiting Sierra Leone. Public Health England was consulted throughout the planning process and was satisfied that measures being taken were adequately robust."