A four-month-old boy is undergoing surgery after allegedly being slashed in the face with a knife multiple times by his grandmother in Brisbane.
The mother, who was visiting the home with her baby, was woken just after 6am on Tuesday by the sound of her child crying in his cot.
The 64-year-old grandmother was nearby, and a large knife was also found at the scene.
"The mother found the child in a distressed state with injuries to his face," Inspector Daniel Bragg told reporters.
"She's clearly distraught over what's occurred. She's provided police with all the assistance she could."
Insp Bragg said paramedics who were called to the home at Ridgeway Street at The Gap, as well as the first police officer on the scene, were visibly upset.
"It was distressing to see such injuries to such a small child," Insp Bragg said.
"This is the worst-case scenario."
The grandmother is assisting police with their inquiries but charges have not been laid at this stage.
"Clearly when a young child has sustained such critical injuries this isn't the work of a well-adjusted, happy individual," Insp Bragg said.
The baby was rushed in a critical condition to the Lady Cilento Children's Hospital, where his mother is by his side.
A hospital spokesman says the boy undergoing surgery but his condition is not known.