The two were found in a parked car in Pyoseon-myeon, Seogwipo, at around 6:08 p.m. on Oct. 12, The Korea Herald reported, citing the Jeju Fire and Safety Headquarters.

The father, an Australian permanent resident in his 40s, brought the girl to South Korea in October 2025 amid a custody battle with his wife in Australia, the newspaper said.

The mother won a ruling from the Seoul Family Court on March 30 ordering the girl's return under the Hague Convention on the Civil Aspects of International Child Abduction, Seoul Economic Daily reported. The treaty is meant to return children who have been wrongfully removed to or kept in another country.

By the time she traveled to South Korea to collect her daughter, the father had already moved with the girl from Seoul to Seogwipo, the newspaper said.

In early April, she reported her daughter missing and asked police to help enforce the court order.

An appeals court upheld the return order on Sept. 30, Kyunghyang Shinmun reported.

On Oct. 2, the mother, by then back in Australia, learned that the father had told the girl's daycare center in Seogwipo that she would stop attending because they were moving to the U.S., Seoul Economic Daily reported. At her request, an Australian court canceled the girl's passport the next day, blocking her from leaving South Korea.

She also asked the Jeju Provincial Police Agency to find her daughter and protect her, warning that the father had mental health problems, was not properly taking his medication and had talked of leaving for the U.S. with the girl. She said she received no response.

"What more could I have done?" she said. "From another country, I contacted the authorities every day and pleaded with the police, and yet this still happened."

Eight checks found no risk

Jeju police said at a briefing on Oct. 14 that officers and municipal child protection officials had checked on the father and daughter in person eight times between Nov. 10, 2025, and July 27, 2026, and found no evidence of abuse or other risk factors, The Korea Herald reported.

Police said they did not open an investigation after the mother's Oct. 2 call because "we had not received the relevant family court ruling on the child's return and the mother's request was not considered a formal report filed through the 112 emergency hotline."

They also said they had no authority to enforce custody-related court orders. "The incident occurred while we were still assessing whether there was any basis for police intervention," the agency said.

Police are investigating how the two died, Korea JoongAng Daily reported.