CHICAGO, Illinois (CNN) -- Authorities will investigate an Illinois cemetery after a bone found on the ground there was determined to be human, a sheriff's spokesman said Saturday.
On Friday, a worker dropping off vaults at Mt. Glenwood Cemetery, in Glenwood, Illinois, noticed a bone lying on the ground, Cook County sheriff's office spokesman Steve Patterson said in an e-mail.
The bone was located in an area where vaults, old headstones and other cemetery materials are stored, Patterson said.
The worker contacted authorities and the bone was taken to the Cook County Medical Examiner's office, which determined that it was human, Patterson said.
"Based on that information, the sheriff's police will now start an investigation, which will include interviewing those working at the cemetery, among others," he wrote.
"I don't know whether this is a sign of a greater problem or if there is a valid reason why this bone was found where it was."
The discovery comes days after three people filed a lawsuit against the cemetery alleging "unauthorized tampering with grave sites, including the apparent removal of a headstone," according to a court document posted on the Chicago Tribune's Web site.
Attempts to reach the cemetery for comment were not successful.
Patterson acknowledged the lawsuit, which was filed in the Cook County Circuit Court on Monday, but said he did not "know if there is a correlation between the civil suit and this bone."
He said there was no reason for authorities to close the cemetery.
Additional details on the bone were not immediately available.
Earlier this month, authorities said workers at Burr Oak Cemetery in Alsip, Illinois, dug up hundreds of graves and resold them.
Four people face felony charges for their alleged involvement.
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