Qld man accused of assaulting newborn son

A Queensland newborn baby is in a critical condition with broken ribs after an alleged assault by his father.

The seven-week-old boy may not survive his injuries, a court has heard.

His father, who cannot be named for legal reasons, wept and had his head in his hands throughout his appearance in Brisbane Magistrates Court on Saturday.

The Sunshine Coast man has been charged with grievous bodily harm but that would be upgraded to murder or manslaughter if the boy succumbs to his injuries, the court heard.

Prosecutors say the boy was in his father's care when the alleged assault happened.

He claimed the baby suffered an "unfortunate accident" but a doctor said his injuries were inconsistent with his story, police prosecutor Matthew Kahler said.

"What happened, happened on his watch," Sergeant Kahler said.

"Fractures of the ribs, et cetera, are not consistent with his version. That's significant, your Honour."

"It's uncertain as to how the child's health will progress over the coming days and weeks.

"Certainly, he is a risk of dying."

The boy was taken to hospital on the Sunshine Coast last week with significant injuries before being transported to the Queensland Children's Hospital in Brisbane.

The man, who also faces a charge of possessing dangerous drugs, was refused bail.

Magistrate Michael Quinn deemed him an unacceptable risk of failing to appear in court and interfering with witnesses.

Mr Quinn said the case against him was strong.

He was remanded to next appear in court on September 16.