Officers attended the Haven near to the footpath at Wormgate at 8.30am yesterday after a body was seen floating in the river.
Lincolnshire Police say that following inquiries, it is believed the man is Scott Butler, who is local to the area.
Formal identification has not yet taken place.
A major search operation involving police, the fire service, and coastguard and police helicopters as well as police drones began after a man was seen jumping into the river on 23 December.
Police were called after a man was seen to jump into the river in the High Street area of the town.
Despite extensive searches at the time, the man was never found.
Police say they believe the incidents on the 23 December and yesterday are connected.
A statement said: “There appear to be no suspicious circumstances and the matter has been passed to the coroner.”