A Sydney father whose newborn baby died at just three months old has told an inquest he's seen the infant's mother smoke ice "more times than I've seen her go to the toilet".
A coronial investigation is examining the sudden deaths of two half-sisters, known as BLGN and DG, who were three-months and 19 days old respectively when they lost their lives in 2014 and 2015.
The father of BLGN, who is in jail, said his former girlfriend suffered a crippling ice addiction which could keep her awake for 10 days straight while her kids were “running amok”.
“I've probably seen her smoke more times than I've seen her go to the toilet,” he told Glebe Coroners Court on Tuesday.
He said he was high on ice three days before BLGN’s death when he went to the mother’s unit with two other men, who smoked the drug in front of her older children.
The trio then left the house but the father said he later returned to the unit and stayed with his baby “until the sun came up”.
“I was laying down and she was resting on top of my heart and I sang to her ‘You Are My Sunshine’,” he said.
“That’s the last time I saw my daughter alive.”
Police found an ice pipe on top of a baby steriliser at the house the day BLGN was discovered unmoving in her cot, which was crowded with toys, blankets, an adult-sized pillow and two baby bottles, the court has previously heard.
The grandmother gave evidence, saying she saw bruises on the baby’s dead body, which she believed was “rigamortis”.
She denied ever smoking ice in front of her three grandchildren and being high when emergency services arrived at the scene.
Deputy State Coroner Harriet Grahame asked the witness what was going through her mind during that time.
“Did you ever try to stop? Did you realise that something needed to change?” the coroner said.
“At the beginning I thought everything was fine … but the death of (BLGN) forced us to realise,” the grandmother replied.
Around six months later, the mother was pregnant again and high on ice when she was taken to hospital after a serious high-speed car accident, the court heard.
The newborn, who the court heard had a heart abnormality, was taken into out-of-home care but died within three weeks.
© AAP 2018