A 48-year-old man from Neath has been arrested on suspicion of the murder of Richard Andrews.
Richard Andrews' body was discovered in September last year - a year after the last confirmed sighting of him. He was reported missing in January 2018 after last being seen in September 2017.
Mr Andrews, from the Melyn area of Neath, was found by a member of the public on the banks of the River Neath.
The 48-year-old man arrested is currently in police custody.
As part of the investigation Crimestoppers is offering £10,000 for any information that could help the police.