Sister of serial wife killer Drew Peterson's alleged victim says she thinks she has FINALLY found the missing 23-year-old's remains dumped in an Illinois canal

The body of one of the fourth wife of killer Drew Peterson has been found at the bottom of an Illinois canal, according to her sister.

Stacy Peterson, the 23-year-old fourth wife of the infamous cop-turned killer, went missing in 2007, and her body has never been found.

Drew Peterson, who is serving 38 years for the murder of his third wife, was never charged in her disappearance but always remained the main suspect. The now-70-year-old killer was 49 when she went missing.

Stacy's sister Cassandra Cales now claims she has located her body in a in a canal in Lockport, 35 miles outside Chicago, sharing underwater footage of the alleged remains with News Nation.

Cale claims she has shared her information with local police and the FBI, but police did an insufficient search of the canal.

'They were floating on top of the water the whole time,' she said. 'And when I was there they didn't even talk to me and treated me like a criminal, and at the end they told me the area is cleared.'

'It’s somebody,' Cales said, adding that she's collecting funds to recover the remains. 'Whether it’s my sister or not, they need to be brought home.'

DailyMail.com has reached out to the Bolingbrook police department and Illinois state police for comment on Cales' claims.  

Peterson, a former Bolingbrook Police officer, was sentenced to 38 years in prison for the 2004 murder of f his third wife Kathleen Savio in 2013.

He and Savio were divorced when her body was found in a bathtub; her death was initially ruled an accident but police reopened the case after Stacy went missing.

Peterson was also convicted in 2016 of plotting to kill the prosecutor who convicted him and sentenced to an additional 40 years in prison.

When previously asked about Stacy's disappearance, Peterson has said he doesn't know what happened to her, and claimed she probably went off the radar on her own.

He claimed: 'Her mother did the same thing and disappeared like that. Stacy always loved and admired her mother. So, if Stacy did what her mother did. I could believe that all day long.' 

In 1998, Stacy's mother, Christie Marie Cales, was last seen strolling a street at 4.30pm in the Chicago suburb of Blue Island before going missing.

Her boyfriend told authorities that Cales had left and never returned but Stacy's surviving siblings insist she was murdered.

In an interview with Ashleigh Banfield, Peterson also talked about Savio and described her as 'boisterous and combative.'

'Kathy, my third wife, she’d fight at the snap of a finger, she’d just want to argue all the time. She was a very, what's the word? Well, she was very Italian. She was very boisterous, very combative. It had to be her way or no way. And I didn't really put up with that,' the murderer said.

When questioned why he won't confess to his crimes, Peterson said he did not want his 'children to think he killed their mothers'.

The pair began dating when Stacy was only a teenager, something Savio found out about after receiving an anonymous letter in the mail in 2001.

'She called me and she said, 'I got a letter, and it said– he was having an affair, and she was a laughingstock,' Sue Doman, Savio's sister, told Dateline.

'The thing that really stood out with Kathleen was that [Stacy] was a baby. She said, 'I don't understand why he would do this.''

Savio wanted a divorce following the revelation and demanded half the investment in the house and half of Peterson's pension.

During his trial, prosecutors claimed Peterson killed Savio because he feared their pending divorce settlement would wipe him out financially.

When Savio, 40, was found dead, she had a two-inch gash to the back of her head and the tub she was in was dry. But police at the time deemed her death an accident, believing she had slipped and fallen.

After Stacy disappeared, authorities became increasingly suspicious of Peterson.

Savio's body was exhumed and her death was reclassified as a homicide. Peterson was arrested in May 2009.

A friend testified that Savio told her Peterson once pointed a knife at her and said 'I could kill you and make it look like an accident.'

A former co-worker of Peterson's claimed that the cop had offered him $25,000 to hire a hitman to kill Savio, although he had never followed through.

Peterson is due for parole in 2047 at age 93.