Perth dad arrested after newborn baby allegedly assaulted

A newborn baby is fighting for life in Perth Children's hospital, allegedly assaulted by her 25-year-old father Juan Daniel Visagie.

The Gosnells man has been charged with grievous bodily harm, as police investigate how the young child received her critical injuries.

The 30-day-old girl was taken by her parents to Armadale-Kelmscott Memorial Hospital on Friday, September 4 just before midnight.

Doctors identified serious injuries that are believed to be life-threatening and alerted police. 

The home on Wheatley street was cordoned off as a crime scene over the weekend, with neighbours telling Nine News they heard the baby crying the night of the alleged incident. 

Police arrested Juan Visagie on Monday, September 7 and are investigating if he shook the baby girl.

Nine News understands the mother was also home at the time but in another room.

The 25-year-old father posted on social media on August 7.

"My daughter born 5 mins ago both the mum and daughter are doing well," the post said.

"Proud dad/mum right here!"

Juan Visagie appeared briefly in Armadale court today where the matter was adjourned for a week.

The court was told the adjournment was to ascertain the status of the victim, with concerns the baby's condition could deteriorate and the charges may need to be upgraded. 

He remains on remand in Hakea Prison.