Stephen Pollard, 58, was reported missing on February, 27, 2015. His body was then discovered in the Beal area on May 22 that year.
At the time the death was not treated as suspicious, but new information came to light and officers are re-examing the case. The family of Mr Pollard have been informed
Two men from the York area aged 24 and 52, and a man from the Wakefield area, aged 52, have been arrested on suspicion of murder and remain in police custody.
Detective Superintendent Nick Wallen, from the Protective Services (Crime) team at West Yorkshire Police, said: “Enquiries into the incident remain ongoing and I would urge anyone who has information about how Mr Pollard died to come forward.”