DENVER (AP) — Human remains discovered in Colorado may belong to another victim of a suspected serial killer with Utah ties, the Denver Post reported.

Eagle County sheriff's officials say human remains were discovered in a backcountry area of Vail Pass Monday during a search as part of an FBI investigation.

FBI spokeswoman Kathy Wright confirms that agents were in the area Monday. Wright declined to say whether the search was part of its investigation into Scott Lee Kimball, 42, who has connections to four people who disappeared in 2003 and 2004.

The newspaper, however, says an unnamed source close to the investigation believes the remains are those of Terry Kimball, 60, Scott Kimball's uncle.

Scott Kimball is a former cooperating witness for the FBI. In March, he led investigators to the remains of Leann Emry, 24, in a remote canyon in southeastern Utah. He also claims to know the whereabouts of another woman's remains in the same area.

Scott Kimball has not been charged in any of the disappearances or deaths. He is a former FBI informant who is being investigated in connection with the deaths of four people but has never been charged. Emry, Terry Kimball, Kaysi McLeod, 19, and Jennifer Marcum, 25, all disappeared in 2003 and 2004.

Scott Kimball told police Marcum's body is in the area of Dry Canyon, near the site where the bones believed to be Emry's were found, Grand County Sheriff Jim Nyland said earlier this year. Marcum was a dancer at a Denver-area strip club when she vanished in 2003. Her car was found abandoned at the Denver International Airport.