A body found in the River Nene in Northampton earlier this month was 32-year-old Artur Liana, police said.
Identification was made after DNA tests and officers do not believe there are any suspicious circumstances. A report will now be prepared for the coroner.
The Polish security guard went missing on 22 December. It is thought he may have fallen into the river after a night out in Northampton.
The last known CCTV footage shows Mr Liana on St Giles Street at 01:35 GMT.
Emergency services recovered the body from the river Nene near The Lakes Business Park on 1 February.