Ricardas Puisys, 35, vanished without a trace from his home in Wisbech, in September 2015, sparking a police murder investigation.
However, police found the missing man five years later in 2020 in a wooded area of Wisbech and the story was told on 24 Hours in Police Custody.
The last confirmed sighting of the Lithuanian national was at his workplace, Nightlayer Leek Company in Chatteris, on 26 September 2015.
Detectives feared Mr Puisys might have been the victim of a serious assault in the hours before his disappearance.
Officers received information which led to them to search a wooded area of Harecroft Road in Wisbech.
Mr Puisys was found living “well concealed” in undergrowth.
A spokesman for Fenland Police said: “The investigation involved some unbelievable revelations along the way and uncovered suspected exploitation and modern slavery.”
The episode of 24 Hours in Police Custody is set to air again on Channel 4 at 9pm on Thursday.
