Updated

A recent Washington State University graduate and her Idaho fiancé may have fled to Mexico with missing 2-year-old Seraya Aung Harmon, according to the Pullman Police Department.

Seraya was last seen with her 21-year-old father, Aaron Aung of Moscow, Idaho, on May 29. That same day, Aung's fiancée, 21-year-old Nadia Erika Cole, was last seen at the Seattle International Airport preparing to leave for a family vacation in Italy, according to police and a statement from Cole's family.

"Initially, Aung was thought to have traveled to Montana because he was seen buying camping gear and a Montana map book in Moscow," police said. "However, the investigation later revealed that Aung and Cole likely traveled to Mexico in a black 2014 Cadillac XTS with Idaho license 1L5147U."

Authorities on June 5 issued an arrest warrant for Aung for first-degree custodial interference for allegedly violating a court-ordered parenting plan. Seraya was scheduled to be returned to her mother on June 3, police said.

RECENT WSU GRAD'S DISAPPEARANCE FROM SEATTLE AIRPORT TIED TO MISSING IDAHO MAN, TODDLER

Seraya Aung

Seraya Aung was supposed to be on a fishing trip with her father, Aaron Aung, in Montana until June 3. (Facebook)

Cole is not Seraya's mother, her family's private investigator previously clarified.

Cole's Instagram shows her engagement to Aung in November 2023. Cole's family issued a statement after her disappearance.

MISSING NORTH CAROLINA GIRL'S STEPFATHER CONVICTED OF FAILING TO REPORT CHILD'S DISAPPEARANCE

Nadia Cole and Aaron Aung

Nadia Erika Cole was reported missing from the airport on May 29, according to the private investigator her family hired. (Instagram)

"It is with deep concern and heavy hearts that we address the public regarding the sudden disappearance of our beloved daughter, Nadia," Beata and Kirk Cole said in the statement shared with Fox News Digital. "Nadia recently graduated from Washington State University with honors, marking a significant achievement in her academic journey."

CLICK HERE FOR MORE TRUE CRIME FROM FOX NEWS

The 21-year-old graduate was "on the brink of embarking on a celebratory family vacation trip to Italy, a trip she and her mother had eagerly planned for over a year," her parents added, but their exciting plans "turned into a nightmare when Nadia left her belongings at the gate to use the restroom and never returned."

Nadia Cole

Nadia Cole was last seen at Seattle International Airport. (Instagram)

"Security footage revealed Nadia hastily exiting the airport with a distressed expression," Kirk and Beata said.

CLICK HERE TO GET THE FOX NEWS APP

Aung is described as 5 feet, 9 inches tall, weighing about 135 pounds with black hair and brown eyes.

Anyone with information about the three disappearances is asked to contact the Pullman Police Department at PoliceTips@pullman-wa.gov or the FBI at 1-800-CALL-FBI (225-5324) or tips.fbi.gov.