West Midlands Police said that remains, found on land off Damson Parkway, Solihull, are not currently being linked to "any criminal investigation".
In 2006, nearby land, just off Old Damson Lane near Birmingham International Airport, was searched by police looking for missing boys David Spencer and Patrick Warren.
At the time police suspected former Shropshire agricultural worker and convicted child killer Brian Field of having kidnapped the youngsters.
Field was jailed for life in 2001 for the rape and murder of a 14-year-old boy.
Officers visited Field in prison in 2006 and questioned him about the disappearance of David Spencer and Patrick Warren, but he denied any involvement.
In a statement today, West Midlands Police said it was expected to be several weeks before they were able to find out how long the remains had been there.
A spokesman said: "We are working with the coroner and building contractors as our investigations continue into the discovery of human remains on land off Damson Parkway, Solihull, on Wednesday, November 4.
"Various scientific tests are required to establish how long the remains have been there which will take several weeks.
"We are not currently linking the find to any criminal investigation."
Field, who used to work as a milking machine engineer in north Shropshire in the 1980s, was a prolific offender and was twice jailed for offences in the county.
While living in Shropshire he was convicted and fined at Wrexham Magistrates Court for gross indecency, after he passed obscene notes to undercover police in a public lavatory.
In November 1972 he was jailed for two years at Aberdeen Sheriff's Court for indecently assaulting a 14-year-old boy who he pounced on along a country lane.
In April 1982 he was fined for gross indecency at Oswestry Magistrates Court after fondling a 17-year-old boy, then in September 1983 at Shrewsbury Crown Court, Field was jailed for four years after being convicted for two serious sexual offences.