A US couple remained in Qatar on Monday a day after being prevented from flying home despite being acquitted of parental neglect over their adopted daughter's death, their representative said.
Matthew and Grace Huang were arrested in January 2013 after the death of eight-year-old Gloria, who had been adopted from an orphanage in Ghana.
An appeals court in Doha on Sunday ruled them not guilty and said they were free to leave.
However, the Huangs were prevented from leaving Doha after spending "10 hours" at the airport accompanied by US Ambassador Dana Shell Smith, their representative Eric Volz told AFP.
He said a "new arrest warrant" was issued even after they were cleared of all charges, adding that it was "not enforced despite the presence of police at the airport".
"We are waiting for the United States and the Qatari officials to resolve this mess," Volz told AFP by telephone from a Doha hotel where he and the Huangs were staying.
An American embassy spokesperson declined to comment.
US Secretary of State John Kerry on Sunday welcomed the court ruling but urged Qatar to allow the couple to return home "without further delay".
"We are deeply concerned about new delays that have prevented their departure," he said in a statement.
Kerry said he had spoken to Foreign Minister Khaled Mohammed al-Attiya, and called on Doha "to immediately implement the court's decision and permit their return to the United States without further delay".
The Huangs, who are of Asian descent, were initially accused of starving Gloria to death to sell her organs, but were later jailed for three years for parental neglect.
They insist that Gloria died of an eating disorder rooted in a troubled early childhood.
They were released in November last year pending trial, but the court denied their request to leave Qatar so they could join their other two adopted children in the United States.
Adoption and multiracial families are rare in Qatar, a conservative Arab emirate, and the family's supporters maintain the Qatari authorities misunderstood the Huangs' situation.
The public prosecutor originally pushed for the death penalty for the couple.
The Huangs moved to Qatar in 2012 for Matthew, an engineer, to work on infrastructure projects linked to the 2022 football World Cup.