The remains of a missing man washed up on the beach near Fleetwood spent months in an office before somebody realised what it was.
A “sizeable” piece of bone that was handed in to rangers at Rossall Point last year was given to police only three weeks ago after it was suggested it could be human.
It was found by two teenage girls walking along the beach.
Detectives now want to speak to the girls in the hope they can lead them to where the rest of the body may have washed up.
Tests showed the bone was from the body of Brice Veevers, who was reported missing in September 2013.
The search is now on for the rest of his body, which it is thought may have washed up somewhere on the Fylde coast.
Det Insp Jason Richardson, of Blackpool CID, said: “This was brought to our attention three weeks ago by one of the volunteers who had come across this bone in the office and was of the belief it could be human.
“It had been handed in several months prior by teenagers and the rangers took possession of it.
“Lots of things do get washed up on the beach and at the time their belief was that it was not human so nobody contacted the police.”
However, one of the rangers came across the bone last month and handed it in at Fleetwood Police station after becoming suspicious of its origin.
Scientists in Dundee established the bone was human and forensic experts were able to extract the DNA which police were able to match up against the Missing Persons Database.
Mr Veevers, from Beeston, Nottingham, was 27 when he went missing from a Blackpool guest house, where he had been staying with a friend.
In October 2013, police appealed for information about his disappearance, saying he had last been seen talking to a woman at the Soul Suite bar, on the Promenade, on September 28. However, police were unable to find any trace of him until they learned of the girls’ grim discovery.
Now detectives are trying to track down the teenagers in the hope they can help them narrow the search for the rest of Mr Veevers’ body.
Det Insp Richardson added: “The two teenage girls are believed to have located a sizeable piece of bone somewhere between Cleveleys and Rossall Point.
“No details were taken when they handed it over and we are very keen to identify who these girls are.
“If we can narrow down the search area be knowing where it was found, we have specialist advisors who can look at tidal patterns and try to recover further remains.
“At the moment, the search area is too wide to do anything.”
Det Insp Richardson said Mr Veevers’ death was not being treated as suspicious.
He added: “This is a very sad set of circumstances for the family and friends of Mr Veevers and my thoughts are very much with them at this time.
“We are keen to find out exactly whereabouts on the beach the bone was discovered so that we can begin a search of the area and we would urge the two girls who handed the bone in to the rangers to come forward.
“I would also urge anyone else who uses the beach and may have found anything similar to get in touch with any information that could assist us with our search.”
Anyone with information is urged to call Blackpool Police 101.