Police searching for the mother of a toddler believed to have been abandoned by her father at a train station in Australia found a woman's body locked in the trunk of a car at the family's New Zealand home Wednesday.

The body was not immediately identified but the car was registered to the father of the 3-year-old girl, and the inquiry into the mother's whereabouts is now a homicide investigation, Detective Senior Sergeant Simon Scott said.

Authorities found Qian Xun Xue alone and confused at a station in the southern Australian city of Melbourne on Saturday. Police in Australia, New Zealand and the United States as well as Interpol are looking for her father, Xue Naiyin, a 54-year-old Chinese-language magazine publisher.

Security video showed a man, believed to be Xue, accompanying the girl in the station then leaving her by an escalator. He boarded a flight to Los Angeles soon afterward, police said.

Father and daughter had traveled together to Melbourne from New Zealand last Thursday.

Police have said they were gravely concerned about the girl's mother, Anan Liu, also known as Anni, because she had not come forward after news broke about her daughter being found in the train station.

Scott said Wednesday the body was found in a car outside the family home in the northern city of Auckland. A post-mortem examination would be carried out Thursday to identify the body.

He said Liu was last seen about 10 days ago. Earlier, Scott had said that police had been called to the home in the past year about "family violence incidents."

Meanwhile, Liu's mother was planning to travel to Melbourne to pick up her granddaughter, said Pansy Wong, a New Zealand lawmaker and ethnic Chinese community leader who spoke to the grandmother in China's Hunan province.

Qian Xun Xue, who was nicknamed "Pumpkin" by rescuers before she was identified, was born in New Zealand after her parents moved there in 2002.