AMERICAN FORK — The American Fork family embroiled in a custody battle over their adopted baby has received a letter from the biological father's attorney that politely requests they give the baby back.

During a court hearing last week, an Idaho judge gave the birth father, Matt Tenneson, 20, of Coeur d'Alene, temporary primary custody of the 5 1/2-month-old baby.

But Jed and Callie Nielson, who have had the baby since June, say they won't give baby Harvey back without a legal fight. In fact, they say they are thinking optimistically and have been buying Christmas presents for the baby.

"We plan to celebrate Christmas with Harvey and be grateful for every day we have him," said Callie Nielson.

"We're just going to keep fighting," she said.

The Nielsons are now being represented by adoption attorney Larry Jenkins, with Wood Crapo LLC, of Salt Lake City.

Jenkins, who graduated from Brigham Young University's law school in 1986, has handled thousands of adoptions for families in Utah and other states.

He also is chairman of the Utah Adoption Council's legislative committee, which works with the Utah Legislature to improve adoption legislation in Utah.

Jenkins said he is reviewing the case and working on strategy.

"It's early in the game," he said.

On Monday, Jenkins said the letter from Tenneson's attorney was an introductory statement, letting him know that Tenneson had hired an attorney in Utah in addition to his attorney in Idaho.

The Nielsons said there was no deadline stated in the letter for the baby to be returned. Jenkins said the letter, which arrived over the weekend, "made no strong demands."

"It doesn't change our direction or our focus," he said. "Our goal is to keep the little boy with the Nielsons."

LDS Family Services, which handled the Nielsons' adoption, is appealing the custody issue to the Idaho Supreme Court. LDS Family Services has employed Idaho Falls adoption attorney Kent Foster.

As an agency, LDS Family Services is reserving public comment until after the court case is resolved.

Kootenai County District Court judges have ordered documents pertaining to the Tenneson case to be sealed due to the high-profile nature of the case, court clerks said Friday.

The birth mother, Cammie Knight, 19, of Coeur d'Alene, says Tenneson didn't sign papers she gave him declaring his paternal rights, and he also didn't sign up with Idaho's "putative father" registry. A putative father is a man who may be the child's biological father but who is not married to the child's mother on or before the date of the child's birth and has not established his paternity through legal proceedings.