A 42-year-old woman believed to be the mother of two children whose remains were found in suitcases bought from a storage facility in New Zealand has been arrested in connection with their alleged murders.

The woman, who has not been identified, was arrested in early hours of Thursday local time in the southeastern city of Ulsan, a South Korean police official told CNN.

The police official confirmed that the arrested woman is the same woman believed to be the children's mother, according to earlier police reports, who arrived in South Korea several years ago and had not departed the country since.

New Zealand police said in a statement they requested an arrest warrant for the woman under the country's extradition treaty with South Korea and have applied to extradite her to New Zealand to face charges.

"To have someone in custody overseas within such a short period of time has all been down to the assistance of the Korean authorities and the coordination by our (New Zealand) Police Interpol staff," said New Zealand Detective Inspector Tofilau Fa'amanuia Vaaelua in a statement Thursday.

The woman will remain in custody while awaiting the completion of the extradition process, Vaaelua added. The woman's identity is being withheld to avoid potentially identifying the children.

South Korean authorities confirmed last month that the woman was born in South Korea and acquired New Zealand citizenship a "long time ago."

Seoul High Court will now decide within two months whether to extradite the woman to New Zealand.

New Zealand police launched a homicide investigation last month after a family in South Auckland reported finding human remains in suitcases they bought in an online auction from a storage facility.

The children -- likely to have been between ages 5 and 10 -- may have been dead for around three to four years, according to New Zealand police.

At the time, police stressed the family who bought the suitcases were not under investigation. (CNN: Text, excluding headline)

Update news