Radiocarbon dating has now taken place of a partial human skull which was found by the river in Barford on the evening of Tuesday 5 May.
Detective Chief Inspector Caroline Corfield from Warwickshire Police said: “Specialist tests have now confirmed the skull - which was found by a member of the public - is from the Medieval period of around 960-1150 AD.
“When the skull was originally discovered, we are aware there was some speculation that it could have been linked to a number of ongoing regional investigations.
“While we always maintained an open mind, it is now clear this is not the case and any families who were awaiting an update have been informed.”
The skull will now be used for forensic training purposes.