The High Court at Auckland, where a woman has been on trial for the attempted murder of her son.

A mother has been found guilty of attempted murder after trying to kill her disabled adult son.

The woman, who cannot be named for legal reasons, has been on trial at the High Court in Auckland.

According to the Crown, the woman intended to kill her son by drowning him in the Manukau Harbour on May 13, 2018.

The man was found alive the next morning on rocks at the end of a beach in Weymouth, south Auckland by a passerby.

READ MORE:

*Mother on trial for attempted murder of disabled son

*Sexual abuse allegations before mum allegedly tried to murder disabled son

*Mum spoke of 'apocalypse' before alleged murder attempt, court hears

*Mum accepts memories of the day she allegedly tried to kill disabled son are 'false'

The defendant's lawyers Jonathon Hudson and Paul Borich QC said there wasn't reliable evidence that the drowning attempt happened and there were issues with whether the woman was capable of forming intent.

The woman's adult son has a severe intellectual disability, epilepsy, autism, Tourette syndrome, schizophrenia and is non-verbal.

During the trial, the jury heard evidence from several witnesses who saw the woman on the day of the alleged murder attempt, who described her as being distressed and speaking into an "invisible walky-talky".

One man said the defendant told him there had been an "apocalypse" and "armageddon".

An interview with Detective Adam Tucker, in which the woman confessed to and demonstrated trying to drown her son, was played to the court.

When the woman gave evidence, she admitted she had told her former partner she had drowned her son, but said she now did not believe she had, as many of her memories of that day – including interacting with Russian president Vladimir Putin's "right-hand man" – had been proven to be wrong.

The woman's partner told the court she blamed herself for sexual abuse her son had allegedly endured in care and had not slept for at least 48 hours before the alleged murder attempt.

Psychiatrist Dr Mhairi Duff, who examined the woman, told the court she believed the woman may have been experiencing automatism - a mental state in which the person can't form intent.

However, under cross examination from prosecutor Mark Williams, Duff said someone who went into the water and held someone else under until they drowned would have intent and could not be said to have automatism.

After more than 11 hours of deliberations over three days, the jury reached a majority verdict on Wednesday.

Eleven jury members believed the woman attempted to murder her son. One did not. The woman was found guilty.

She is due to be sentenced on February 14, 2020.