A witness had attended the compound, which was locked and secured with barbed wire, to see if the truck was still drivable.
When he got there, he found the front window of the truck had been smashed in, the curtain inside had also been cut and the engine wouldn’t start.
He then looked through the curtain and he saw what he thought was a dummy that has been used in the film - but it was actually Roberts’ body.
The court heard how the owner of the truck then drove to London to try and get the engine to start, which is when he discovered the body.
The police were called and Roberts was pronounced dead on December 2.
Assistant coroner Sarah Murphy read a statement from Roberts’ GP who said he had been seen on several occasions for anxiety and depression.
He was on prescribed treatment for his mental health and was put in contact with a crisis team after expressing suicidal thoughts on one occasion.
Contact was made with Roberts on various occasions to check in but he said he was not expressing suicidal thoughts and was depressed.
During the hearing, Murphy also read a statement from Detective Chief Inspector Maggie Cassidy who was involved in the case.
She said how a note was found in the truck from Roberts in which he showed an intention of ending his life and that it appeared he had been there for a “prolonged time”.
Cassidy said that there were no suspicious circumstances around his death and Murphy concluded that Roberts took his own life.
Murphy said: “I express my sincere condolences to the family and friends of Ian Roberts for his untimely death.”