The body was discovered Wednesday in a park in the Denver-area city, The Denver Post reported.
Trevor Materasso, a spokesman for the Westminster Police Department, released a brief statement and declined to answer questions, saying there would be another briefing early Thursday.
"We are unable to make a connection to the disappearance of Jessica Ridgeway," he said.
Earlier Wednesday, Materasso told reporters investigators have determined Jessica's parents are not suspects and that she was abducted. He said registered sex offenders in the area are being interviewed, something he described as "standard procedure."
"The focus shifts to an unknown suspect because we think she was abducted," he said.
Jessica left her home in Westminster last Friday, planning to meet schoolmates in a park to walk to Witt Elementary School. She was not reported missing until about 4:30 p.m., because her mother works nights and did not receive a message that her daughter did not turn up at school until she woke.