The mother of Moko Rangitoheriri has given emotional and tense evidence at the inquest into her toddler son's death in 2015.

The inquest into the three-year-old's death began in the Rotorua District Court yesterday in front of coroner Wallace Bain.

Moko's mother, Nicola Dally-Paki, was in Auckland with another child receiving treatment at Starship Hospital at the time of Moko's abuse and death.

He had been left in Taupo with Tania Shailer and David Haerewa while his mother was in Auckland's Starship Hospital looking after another child.

He died on August 10, 2015, after suffering horrendous injuries from beatings and abuse. Shailer and Haerewa were sentenced to 17 years in jail for Moko's manslaughter last year.

Ms Dally-Paki told the coroner's court in Rotorua that she placed Moko and his sister with Shailer because she had known her for 15 years, assumed the children would be safe and because it was a better option than a gang house.

She says she had done everything in her power to keep her children safe.

"Well, I didn't do a police background check and I didn't ask all the social workers what was going on with her mental health, I just made an assumption that knowing her from previous early childhood that she'd be safer as opposed to putting them into a gang life."

Ms Dally-Paki talked about the domestic violence she suffered in her relationship with Moko's father and made an emotional plea to others in similar situations, to leave and never go back.

She says she was in a complicated situation trying to find safe housing for herself and her children and if she had been less harshly judged, her son would still have been alive today.

She says if the authorities had concerns about her children, they had known how and where to find her.

"They did not once contact the Auckland DHB social workers that work at Starship to gather evidence about me and my background for the investigation. If they had, they would have been notified by the Auckland DHB social workers and my Moko would still be alive."

She says if other women were in similar situations, they needed to have an emergency plan, ask for help and not feel ashamed.

Moko's paternal grandmother also gave evidence to the inquest and asked why various agencies had not listened to her concerns.

Nicola Rangitoheriri had offered to have the children, but their mother rejected the offer.

Mrs Rangitoheriri says she had been let down by Child, Youth and Family.

"You didn't help me either. All I basically got was that there was an investigation and putting my hand up to have them meant nothing.

"Please tell me why no one bothered to check on them after a complaint was made against the mother, just to ensure their well-being.

"Tania had four children of her own."

Detective Inspector Lewis Warner, who led the investigation, also gave evidence today, which included texts between Shailer and Moko's mother in the weeks leading up to his death.

The inquest will continue today.

-RNZ