Athena Brownfield: Missing Oklahoma girl 'beaten to death and buried on Christmas'

Court documents say the child, 4, was beaten to death that night by her caregiver

Troopers search a pond near Cyril, Oklahoma, for Athena Brownfield, 4. Oklahoma Highway Patrol / AP

A missing Oklahoma girl, 4, was beaten to death on Christmas night by her caregiver, then buried, court documents released on Tuesday show.

Athena Brownfield has been missing since January 10 when a postal carrier discovered her five-year-old sister alone outside the home the girls shared with the caregivers, Ivon and Alysia Adams, in Cyril, 110km south-west of Oklahoma City.

The search for the child is now a "recovery operation", the Oklahoma State Bureau of Investigation said on Monday.

The notice for Athena Brownfield, 4. Oklahoma Highway Patrol / AP

Ivon Adams was arrested in Arizona on murder and child neglect charges and awaits extradition. Alysia Adams is jailed in Oklahoma on child neglect charges.

An affidavit says Alysia Adams told investigators that her husband beat the child at about midnight on December 25.

Athena “was not moving and her eyes were barely open”, Alysia Adams said, according to the affidavit by OSBI Lt Brenna Alvarez.

Ivon Adams “then laid her on the ground and punched her at least three more times in the chest” and the child “never moved after that”.

The affidavit said he left the home with Athena at about 1am on December 26 and later returned, saying he buried her body on land the couple once owned close to the nearby town of Rush Springs, about 124 kilometres south-east of Cyril, marking the site with “a large broken branch”.

Authorities have been searching that area.

Ivon Adams has waived extradition rights in Oklahoma and remains jailed in Maricopa County, Arizona, pending extradition.

“I want to get there and take care of it,” he told a judge during a hearing Friday in Maricopa County court. “I need to get there and fight this.”

Court documents do not list lawyers who could speak on the behalf of either of the Adams.

Brandon Bryant, who said he and his wife were once neighbours of the Adamses, said on Tuesday that he had little interaction with the couple but saw nothing unusual from them.

“Didn’t see anything out of the normal," Mr Bryant said. "We talked to Alysia a few times, Ivon never.

"We never went into their house. Alysia came over to our house a few times … we gave her a car seat.”

Mr Bryant, whose children are 5 and 10 years old, said he still considers Cyril, with a population of about 800, a safe place.

“It’s a small town, it’s probably one of the few places on Earth I would consider leaving my doors unlocked at night … it’s still a good place to live," he said.

The OSBI has said the girls and the Adamses are related.

The affidavit said that the children's biological mother had left them with the couple between 18 months and two years ago, and that the girls called Alysia “mom” or “Aly”, and Ivon “dad” or “Uncle Ivon.”

The children's biological mother and father are co-operating with investigators, the OSBI said.