Julian Gardner, 53, suffered multiple injuries in the early hours of October 11 last year.
He ran an agricultural and car repair business at Bush Barn Farm, off the A21, near Robertsbridge, East Sussex. The compression-type injuries he suffered are believed to have been caused when he was crushed between two vehicles.
A 25-year-old man from Kent was arrested on Thursday but has now been released on bail until September 5, a spokeswoman for Sussex Police said.
Six men appeared at Lewes Crown Court last month over the killing and a provisional trial date has been set for February 13 next year.
They also face charges of conspiracy to burgle the farm and conspiracy to pervert the course of justice.