Early morning Aztec?

[BSD]

Trying to sleep after a long night flight at 4:30 am (or thereabouts) yesterday morning, a light twin, an Aztec as far as I could tell was operating back and forth near my home which is northwest of Stansted.
Legs seemed to follow a southeast/northwest axis of 10-15 miles. No transponder information on FR24.
Kept it up for over an hour. Tough way for someone to make a living, but what on earth was it doing?
Any guesses?
BDD.

[SpringHeeledJack]

TV License evasion patrol (countryside department) hoping to catch a few of those sneaky farmers out whilst watching the weather report. ;-)

It might have been one of the aircraft that do work for plod ? Or a geo-survey of some kind. Bloody annoying if you're trying to sleep. Got woken up myself by a helo at 4.30am this morning, not a Police steed, so somewhat unusual.

[Jetscream 32]

Im pretty sure it was the Chieftan...