At 1.30pm on Sunday 1 January 2017, police were called by a member of the public reporting that they had seen a body in the river near Holly Terrace, York.
With the assistance of the Fire and Rescue Service, the body of a man was recovered from the water a short time later.
He has been identified as Craig Darren Batters, 42, of York.
Officers are appealing for anyone who may have had contact with Craig between Friday 30 December 2016 and Sunday 1 January 2017 to get in touch.
Anyone with information is asked to call North Yorkshire Police on 101, quoting reference 12170000357.