The bodies of two young children discovered in suitcases in New Zealand – allegedly after having been killed by their mother – contained traces of an anti-depressant drug, a court has heard.

Hakyung Lee, 44, is being tried in an Auckland court over allegations that she murdered her children – eight-year-old Yuna Jo and six-year-old Minu Jo – and hid their bodies in a storage facility.

The remains of the children were discovered inside suitcases by a family who had purchased the contents of the storage unit at auction in 2022.

Traces of the anti-depressant Nortriptyline were later found in the chest cavity and liver of both Yuna and Minu, prosecutor Natalie Walker told the court on Tuesday.

The drug should not be given to children, and in cases of overdose can cause seizures, drowsiness, or death.

Ms Lee was prescribed Nortriptyline as a trial in 2017 after telling a doctor she was having trouble sleeping and felt dizzy following her husband's cancer diagnosis.

She has pleaded not guilty to two charges of murder but accepts she caused the deaths of her children, the court heard.

Following their deaths, she wrapped them in three plastic bags, put them in suitcases sealed with duct tape, and left them in a storage center for four years, as stated by the prosecution.

Prosecutors allege Ms Lee changed her name and a month after the killings, flew to Seoul on a business class seat.

She was arrested in Ulsan, South Korea, in September 2022 after Interpol issued a global red notice for her, and extradited to New Zealand in November of that year.

The grim details of the children's bodies being discovered were revealed in court. On 10 August 2022, two members of the public won an auction for Ms Lee's abandoned storage locker, where they found two suitcases containing the remains of her children.

An autopsy concluded there were no signs of trauma, but the children died by homicide, possibly linked to the Nortriptyline found in their systems.

The prosecution presented evidence of Ms Lee’s mental state, detailing how she had experienced significant emotional turmoil following her husband's cancer and death.

Defense lawyer Lorraine Smith claimed Ms Lee's descent into madness began with her husband’s terminal illness. The defense contends that while Ms Lee is culpable for the children’s deaths, she should not be charged with murder because her state of mind at the time rendered her insane.

As the trial unfolds, the jurors will face the challenging task of determining Ms Lee's mental state at the time of the purported crimes amidst a tapestry of grief, despair, and family tragedy.