Police are investigating after human remains were found in a field on farmland on Easter Monday.
Northamptonshire Police were called to the field in Rothersthorpe at about 10.45am yesterday after the discovery.
A spokesman said: "At this stage it is too early to say how the remains came to be in this location or how the individual died and an investigation is under way to determine these facts.
"Local roads was closed for a short time while the remains were recovered but all routes are now open.
"At this time the death remains unexplained and the remains will be the subject of a forensic post-mortem."
A police spokesman said the post mortem examination is due to take place later today at Leicester Royal Infirmary.
He said the remains were found by a woman walking her dog in a field of elephant grass in farmland off the road between Gayton and Rothersthorpe.
They are believed to be of a man over the age of 21 and between 5ft 7in to 5ft 10in, the spokesman said.
It is thought he may have lain in the field for up to a year, and may not necessarily have formally been reported missing.
Clothing, thought to be linked to the discovery of the remains, has also been recovered by search teams, police said.
They include a grey singlet vest with white piping around the shoulders and neck stamped with Cedarwood State - a Primark brand.
Also recovered were a pair of boxer shorts with a Peacocks label and a pair of "very worn" size eight Nike Air trainers with white uppers, black soles and inserts marked Beckets.
Superintendent Glyn Timmins, who is leading the investigation, said: "We are appealing for anyone with information about this incident to come forward.
"We are presently treating this death as unexplained. We believe the body to be that of a man and the nature of the investigation, in terms of establishing his identity and how he died, may take some time.
"We believe the body may have lain in the field for some time, maybe up to a year, and that because of the nature of the location - close to the M1 and the canal network - that this man might not be local to the area.
"It is also distinctly possible that this may not be someone who has formally been reported as missing."
Mr Timmins urged anyone with any information about who the man could be, how he came to die and how he came to be in the field, to get in touch.