A man who suffered two strokes and could no longer walk or clean himself was left alone without food for hours in a house by his wife, his sole carer, a jury has heard.

Malia Unalotokipea Li denies causing Lanitola Epenisa's death from sepsis, a blood infection brought on by infected sores '"all over his body", some so deep muscle and bone were exposed.

The mother of two is on trial for manslaughter at the High Court in Auckland, almost five years on from his death in October 2016 in Māngere.

Epenisa died sitting in his own encrusted faecal matter, with maggot pupae embedded in his hip and surrounded by bags of his soiled clothes and a nest of mice, the Crown alleged.

A relative of Epenisa visited him while he and his family lived at a Tongan community-operated home on Vine St in Māngere.

Paealata Laukaupo'uli said her son had to climb through the window because they found him locked inside, alone when they came to visit.

Epenisa shouted through the window that he had not eaten.

"Another time I went to visit Epenisa, I knocked on the door and no one was there, I rang Malia and she came back," she told the courtroom.

"When the door was open Epenisa was shouting from the bedroom and he said to her 'Since you've left this morning I haven't eaten'."

Because of Tongan custom, Laukaupo'uli did not want to interfere, she said.

She offered to help Li find a more suitable home for her husband's needs but it never eventuated, she said.

On one visit Laukaupo'uli claims Epenisa asked his wife to go to the toilet. She told him to wait until their daughter arrived home.

"Epenisa said he was desperate to go to the toilet. Malia said just wait."

Malia then "led" him to the bathroom during which he allegedly soiled himself.

When their daughter arrived home she was seen mopping the floor.

Laukauo'uli often spoke to Malia over the phone about Epenisa's wellbeing when the family moved out of the community house and into a home of Malia's relative.

"She told me she often leaves Epenisa with her cousin. I asked her: 'How does he go to the bathroom?' and I was told the cousin takes him."

Malia said Epenisa did not want to go to a rest home.

Epenisa missed doctor's appointments and family gatherings, Laukaupo'uli claimed.

"There was one appointment my daughter was going to take him to, but it didn't happen.

"My son really wanted to see Epenisa on the day of his wedding. He didn't come."

It's the third day in the trial before Justice Wylie.