A Portland woman is accused of offering her 3-year-old daughter to a man paying for sex.
Kelsey Christine Wheeler, 27, claims she never intended to allow her child to be abused but was using her as bait instead so she could rob the man in question, according to federal court records reported by Oregon Live.
FBI agents and Eugene police received a tip-off on 13 April from a man caught viewing child pornography.
Barret Spangler said, in an affidavit, that he had been offered a sexual encounter with Wheeler's daughter for $1,000 (£800).
He claimed he had met Wheeler, who also worked as a prostitute, through a classified website and they had exchanged messages discussing "mother-daughter scenarios".
Spangler then claims that Wheeler offered her child for cash on the condition that she could remain in the room throughout the event.
After receiving Spangler's testimony, detectives visited Wheeler at her Portland apartment and took her to a police station for questioning.
"When confronted with the evidence of the investigation, Wheeler admitted it looked 'very bad' for her," according to court documents.
However, she challenged Spangler's testimony, claiming he had in fact offered her $6,000 for sex with her daughter and that she had played along, planning to rob him of his money while depriving him of sex with the child.
"She was planning to scam the guy. She never intended to involve her child," her lawyer Susan Wilk told Oregon Live.
The FBI also discovered that Wheeler was previously named in a Child Protective Services report from Las Vegas after she was said to have been found in a room with her daughter and a man wearing "minimal clothing". She denies that this occurred.
The morbidly obese mother is also accused of working as a prostitute in Portland as her daughter sat in the backseat of a car.
Wheeler, who remains in custody awaiting trial, told authorities she had been working as a prostitute since the age of 15, but was currently unable to have sex because of her weight. The three-year-old remains living with her mother.