(CNN) -- The biological father of a Native American child was arrested Monday after defying a court order to return the girl to her adoptive parents, the latest development in a four-year case that has spanned state lines and tested an unusual federal law.
Matt and Melanie Capobianco, a white couple from South Carolina, legally adopted Veronica at birth in September 2009. When Veronica's father, Cherokee Nation member Dusten Brown, learned of her adoption a few months later, he asserted his custody rights under the Indian Child Welfare Act, setting off a lengthy legal fight.
A family court judge ruled in Brown's favor in late 2011, and he took his daughter back. The Capobiancos have fought ever since to have Veronica returned.
The case has bounced from family court to the U.S. Supreme Court and back again. After South Carolina's Supreme Court ruled last month to allow the Capobiancos' adoption to be finalized, the U.S. Supreme Court refused to intervene, thus giving the ultimate go-ahead for the Charleston couple to regain custody of Veronica.
The girl's transition back to the Capobiancos was supposed to begin last week. Brown, however, never showed up with his daughter.
A family court judge in South Carolina ordered the girl to be handed over immediately, saying she was being "unlawfully withheld from her lawful parents." The Charleston County Sheriff's Office issued a warrant for Brown on Friday for interfering with custody.
Brown was arrested Monday in his home state of Oklahoma after turning himself in. He posted a $10,000 bond, according to the Charleston County Sheriff's Office and Amanda Clinton, spokeswoman for the Cherokee Nation District Court.
It wasn't clear Monday evening, however, where Brown or his daughter were.
Melanie Capobianco told reporters that Veronica is being "illegally held against the wishes of her parents and the courts," and she pleaded for her daughter's return.
"With every passing hour, we fear more and more for her safety and well-being," she said. "If anything should happen to our daughter while she's being left in the hands of those who hold her captive from us, the responsibility will be shared by many."
She added, "We pray that those who are holding Veronica will do the right thing and send Veronica home to us, please."
Charleston County authorities said they are in touch with Oklahoma officials about extraditing Brown "as well as pursuing all available options in locating Baby Veronica."
Brown told CNN's Randi Kaye over the weekend that he is willing to go to jail for his daughter.
"I'm going to fight till I have no fight left in me and till they say you can't fight no more," Brown said. "This is my daughter. It's not a yo-yo that I can just say, hey, I borrowed it for two years and here's it back."
Brown claims the Indian Child Welfare Act allows him to have parental custody of Veronica over the Capobiancos. The Supreme Court, however, ruled that Brown could not rely on the act for relief because he did not have legal or physical custody of Veronica at the time of the adoption proceedings, which the birth mother initiated without his knowledge.
Brown, who was not married to Veronica's non-Indian mother when she was conceived, signed a legal document agreeing to put the girl up for adoption and relinquishing his parental rights in exchange for not paying child support.
His attorneys say Brown did not understand the extent of the waiver and that the mother never indicated she intended unilaterally to give Veronica up for adoption.
CNN's Marlena Baldacci, Christine Theodoru, Mayra Cuevas, Joe Sutton, Randi Kaye and Bill Mears contributed to this report.