A 10-month-old baby sustained “horrendous” water burns to 40 per cent of his body in circumstances that investigators are treating as domestic violence, police allege, reported SMH.

The baby was at home on Castlereagh Street in Penrith on Sunday afternoon with a 23-year-old man, Detective Superintendent Brett McFadden told reporters.

A 23-year-old man is in police custody and will face court on Monday, accused of beating and burning the baby boy at a Penrith home on Sunday.

“We understand that some of the injuries relate to burning of the skin and about 40% of the child’s body. There are other injuries there that appear to be consistent with blunt force trauma,” Det Supt Brett McFadden told reporters in Sydney on Monday.

Paramedics called the police to the Penrith home on Sunday afternoon where they treated the boy.

The child, reportedly a boy, was taken to Westmead Children’s hospital where he remains in a critical condition in an induced coma, according to Australian Associated Press.

“What we do know is that the biological mother of the child and the 23-year-old male that has been arrested have been in a relationship for the last four or five months and for the last few weeks, they’ve been residing together at the Penrith address,” he said.

The child’s mother was very distressed, McFadden said. “She is with the child at the hospital. We spoke with her at length last night..”

“This 10-month-old received what I would say are significant and horrendous injuries,” Superintendent McFadden said.

“We are considering this as a domestic violence-related matter.”

The man was known to police, he said.

McFadden said the man was not the child’s father, and police had been in touch with the biological father as part of the investigation.

McFadden said the 23-year-old was known to police but would not say in what capacity.