A man received serious leg injuries after an assault in Thetford on Monday night.
Police were called to an address, in St Giles Lane, at about 9.30pm by the ambulance service who were treating an injured man.
The man, who is Russian and in his 20s, had previously been in the river and was taken to hospital with serious leg injuries.
Officers searched the riverbank on Tuesday to establish where the incident took place but nothing was found. Contact Thetford CID on 101.