Police divers are searching the river near Sincil Bank for a weapon after a man was found with stab wounds.
Warning: Some of the photos in this report contain blood.
As previously reported, a man in his 20s was taken to Lincoln County Hospital with non-life-threatening injuries after being found with four stab wounds on Walnut Place in Lincoln at 11.33pm on Wednesday, August 21.
No arrests have yet been made at the time of writing.
A reporter at the scene on Thursday morning saw trails of blood leading up to the police cordon, where another large puddle of blood was left.
They claimed the wound to the shin is to be 4cm deep and wide, with the other wounds around 3cm deep and wide.
As part of the investigation police previously said they put cordons in place in various locations including Walnut Place, Chelmsford Street and Sincil Bank.
Police are appealing for any witnesses or anyone with information to contact them on 101 quoting reference 528 of August 21.