Police were called at 12.10pm on Sunday, June 15, to a report of two men fighting in Owlbeech Wood, Horsham.
When officers arrived both men had left together in the same white van.
The 25-year-old victim, of no fixed address, was later identified and spoken to by officers. He had suffered cuts and bruises.
A 25-year-old man from Rudgwick was arrested and questioned on suspicion of assault and kidnap before being released on bail until July 23.
Anyone with information should call 101 quoting serial 642 of 15/6, email email@example.com or call the independent charity Crimestoppers anonymously on 0800 555111.