Last Updated 1:50 p.m. ET
Investigators picked their way across a muddy stretch of remote central Illinois Saturday as they followed a lead into the disappearance and possible homicide of the fourth wife of former suburban Chicago police officer Drew Peterson.
Peterson already faces a murder charge in the 2004 killing of his third wife, Kathleen Savio.
No one has been charged in the 2007 disappearance of his subsequent spouse, Stacy Peterson, and her body has not been found.
Illinois State Police confirmed Saturday that they are currently following a lead in rural central Illinois regarding Peterson's disappearance and have set up a media staging at a location near Peoria, reports CBS Station WBBM.
The Illinois State Police team that has been investigating the disappearance and possible homicide of Stacy Peterson is at the scene, an ISP release said.
"There is a search underway for human remains; however no human remains have been located at this point," Peoria County Coroner Johanna Ingersoll said as of 10 a.m. CT.
The search is taking place in Peoria County, but Ingersoll could not immediately confirm exactly where the search is taking place or whether the search is related to Peterson.
State police Master Sgt. Tom Burek says several law enforcement agencies, including some from the Chicago area, are searching rural land "thick with timber" near Peoria on foot.
Burek says rains have reduced the land to a "muddy mess," and vehicles haven't been able to get to the entire search area.
He wouldn't say when the search began or how large the search area is. He also wouldn't confirm where the lead came from or how credible police thought it might be.
"We follow up on every lead," he said.
Stacy Peterson's disappearance drew national attention after Drew Peterson was named a suspect in both her disappearance and Savio's death. Stacy Peterson was 23 when she disappeared.
Investigators have followed several leads into Stacy's disappearance over the years, including sending divers into murky Chicago-area waters.
Drew Peterson, 56, is scheduled to go on trial next month, charged in Savio's killing. He has pleaded not guilty to first-degree murder and is being held in isolation at the Will County Jail.
The celebrity website TMZ reported that, according to law enforcement sources, Peterson told a fellow inmate that an accomplice helped him dispose of his fourth wife's body.
Pat Barry, spokesman for the Will County Sheriff's Dept., disputed TMZ.com's report.
He told WBBM, "Ever since Drew Peterson has been in protective custody at the Will County Adult Detention Facility, he is completely alone. Whether on a computer or eating meals he is by himself. He has no contact with any other prisoners. By court order, he is limited to who he can speak with, and the only people he is allowed to talk to are his immediate family and his attorney, no one else."
Joel Brodsky, an attorney for Drew Peterson, also disputed the report. He called the TMZ.com story "ridiculous" and factually inaccurate, saying, "Drew is in isolation. He doesn't have any contact with other prisoners.
"Drew's position from day one has always been that she ran off with another man, because that's what she told him," Brodsky said. "This is just another in a long line of unsubstantiated rumors about Drew Peterson, all of which have proved to be false."