The Bombardier Global Express 6000 aircraft has made a number of take-offs and landing at Doncaster Sheffield Airport in recent weeks.
The plane, which is being modified by the Marshall Group of Cambridge undertook flight tests at the beginning of July. It has also been spotted in Doncaster in recent days.
The jet is reportedly destined for the UAE and is thought to be an electronics and signals intelligence-gathering aircraft.
The plane has previously been pictured at Cambridge Airport.