A pregnant 21-year-old Texas woman attempted to sell her unborn baby to the “highest bidder” and blackmailed desperate would-be adoptive parents in the maternity ward for cash, according to police.

Juniper Bryson posted in September to an adoptive parent group looking for “adoptive parents” just days before her birth.

One of their alleged leads was Wendy Williams, who responded to the post, signed the legal paperwork to adopt the baby and drove to the hospital for the birth, Williams told ABC 13.

But in the maternity ward, she learned that the “adoption” was a scam, she said.

In reality, Bryson had spent the final days of her pregnancy shopping online for the unborn baby, demanding cash payments from prospective parents, and “waiting for the highest bidder in exchange for her son” while she lay in the recovery room, police say.

Her efforts to sell the child began as early as Sept. 21, just three days before the baby's birth, when Bryson asked a distant relative for help finding a home for her son, according to court documents.

The relative then wrote a Facebook post saying: “She needs someone to be there during labor and take the little boy home. “She doesn't want him to go into foster care.”

But in a subsequent message exchange, Bryson told the relative that whoever took the child “must compensate,” phone records show, prompting the relative to respond, “That's illegal!”

The next day, Bryson wrote the message in a Facebook group that connects birth mothers with adoptive parents.

She didn't mention wanting payment, but when potential adopters came forward, Bryson demanded “compensation,” became hostile or stopped conversations at the first sign of hesitation, court documents say.

A same-sex couple was halfway from Louisiana to Houston when they received a message from Bryson asking for a wire transfer of $150. The couple said they wanted to discuss the matter over the phone, but Bryson refused to answer the phone, calling her “full of crap” and writing: “(sic) Don't text me anymore unless it's sent.”

Meanwhile, Bryson reportedly joined other hopeful parents, including Williams, who traveled to the hospital and was present for the birth.

Williams — a licensed foster care provider — learned of the plan after Bryson gave birth on Sept. 24. Bryson named Williams in a Facebook post, sparking a flood of angry messages from concerned internet users.

“A lot of people started commenting really, really ugly things,” Williams told ABC 13. “'How dare you sell this baby?' And then they told me, 'How dare you buy this baby?'”

When she confronted Bryson, Bryson kicked her out of the recovery room.

Williams then called Child Protective Services, who contacted police.

Williams told police that Bryson had talked about a payment, but when she later saw Bryson's message exchanges with other women, it became clear that she was part of a price war in which Bryson was “waiting for the highest bidder.”

Police arrested Bryson on Sept. 26, who already had two outstanding warrants.

The baby tested positive for drugs at the hospital and Bryson agreed to sign documents giving up custody.

Although Williams requested custody, a judge said the child was given to an acquaintance of Bryson, Williams told the outlet.