Miss Webster said the victim had a low IQ and “very little understanding of the world around him”.

She went on: “He was found by the police living in a rotten shed, with water pouring through it, with a make-shift bed, and congealed vomit in the corner. Not the way that anyone would choose freely to live and not where he would be if he could have found himself better living accommodation.”

“He had few possessions to show for his 40 years’ hard work. He only had a wash bag, three second-hand coats, a few stained duvets, and CDs.”

He lived with the Swailes family for many years after being in care as a child, with Swailes Snr telling him he was his “boss”.

When he was not being made to work, Swailes Snr would order him to do chores such as painting the kitchen and cutting the grass.

In a nearby similar-sized shed to the victim’s “accommodation”, there was a fitted carpet, a light, a gas heater and the family dog.

Miss Webster said: “Peter Swailes Senior had a far better standard of living, an elaborate, carpeted home with expensive personal belongings. A palace by contrast to where (the victim) lived.”

When officers attended the traveller site in October 2018, the victim told them he only received £10 a day for his work duties.

Under the plea deal, the prosecution accepted that Swailes Jr was under the coercive control of Swailes Sr.

Judge Richard Archer told Swailes Jr: “You may not have known the true extent of (the victim’s) living conditions, or his precise IQ, but it must have been obvious to you that he did not have any real appreciation for the potential consequences of some of the work that you required him to perform at an undervalue and with little or no regard for his personal safety.”

Sentencing the father-of-five to a nine-month jail term, suspended for 18 months, he said he took into account a pre-sentence report, which assessed Swailes Jr as posing a “very low” risk of reoffending, and also his personal mitigation, including his poor health.