WELLINGTON, New Zealand (AFP) — A woman on trial in New Zealand admitted to killing her children who were later found in suitcases, court records showed Friday, though the mother’s defense has reportedly argued she is not guilty by reason of insanity.

South Korean Hakyung Lee “accepted that she gave her children nortriptyline which led to their deaths,” state prosecutor Natalie Walker told jurors this week, referring to a common antidepressant.

Police believe Lee killed her children — Minu Jo, 6, and Yuna Jo, 8 — in June or July 2018, a year after her husband’s death, and then returned to South Korea.

The children’s bodies were found in an abandoned storage locker by an Auckland family over four years later.

Lee was extradited from South Korea in November 2022 at the request of the New Zealand police.

During cross-examination in court, however, pathologist Simon Stables said it was hard to conclude that the antidepressant was the sole cause of the children’s deaths given the advanced state of decomposition when their bodies were discovered.

“One could argue that it is the cause of death or you could say that it’s in combination with something else,” he told the court.

“It could also have subdued the child,” he added.

The children were found in separate peach-colored suitcases, wrapped in plastic, a police officer who first investigated the matter told the court.

Lee has elected to represent herself in the trial but has two lawyers who are serving as standby counsel.

On Tuesday, defense lawyer Lorraine Smith told the court that Lee was “not guilty of murder by reason of insanity,” video of the trial released by Australian national broadcaster ABC showed.

Smith said the death of her husband in 2017 sent her into a depressive spiral.

At one point, Lee thought it would be best if the whole family died and they all took antidepressants, Smith said.

But she got the dose wrong and when she woke up, the children were dead, Lee said.

Her trial is expected to last four weeks.