'He Was The Light': Mother Mourns Six-Month-Old Son's Alleged Murder

A mother says she has been left "broken" following the alleged murder of her six-month-old son by her new partner.

Jie Smith, 28, appeared in Wyong Local Court in the NSW Hunter Region on Thursday charged over the infant's death.

Police allege Smith had been in a relationship with the boy's mother for about six weeks.

In a statement, she described her son as being "perfect in every way".

"He had a smile that lit up the whole room," she said.

Even on my darkest days he was the light and I’ll forever miss him and forever love him."

Emergency services were called to a home in New Lambton just before 4.30am last Saturday following reports the boy had gone into cardiac arrest.

He was rushed to hospital in a critical condition but tragically died the following day as a result of a  traumatic head injury.

"He suffered horrific injuries, injuries that were so severe they've taken his life," Detective Superintendent John Kerlatec told reporters in Sydney on Thursday, adding the circumstances made it a "difficult investigation".

"I won't go into detail... needless to say it affected everyone that turned up in that location."

Jie Smith, 28, is charged with murder over the death of a six-month-old baby boy. Image: Facebook

Investigators believe the mother was not home at the time.

“I’m so hurt and broken," she said. "No justice would be enough for my baby boy."

"She's doing it exceptionally tough," Spt Kerlatec added.

"I don't think anyone could even begin to fathom the emotional trauma that she's going through at the moment."

Police arrested Smith at Budgewoi about midday on Wednesday and charged him with murder and reckless grievous bodily harm.

His matter was mentioned in court on Thursday where he didn't apply for bail and it was formally refused.

Smith was remanded in custody to reappear on May 1.

The Child Abuse and Sex Crimes Squad comprises detectives who are specifically trained to investigate matters against children, including assault, abuse and neglect. Anyone with concerns about suspected child abuse or exploitation should call Crime Stoppers on 1800 333 000 or online.