In a statement released shortly before 01:00, a Government of Jersey spokesperson said the aircraft – believed to be a Chinook – landed at 23:00 at Jersey Airport.

It then took the patient to Southampton General Hospital.

The spokesperson added: “Military assistance was sought for reasons of patient safety and to avoid any delay in the transport taking place.

“We will not be releasing any more details on the patient in order to protect their confidentiality.”

Numerous islanders took to Facebook last night to question the unusual sound they could hear outside as the low-flying helicopter passed by the island, landed and took off.

One person reported hearing it from as far as Grouville.