A child has died after being hospitalised during a gastro outbreak at a Sydney childcare centre.

But New South Wales health authorities say the death doesn't appear to be related to the illness at this stage.

Five children who attended the Little Zak's Artarmon childcare centre, on the city's lower north shore, were hospitalised over the past week, four of them for gastroenteritis.

One of the children died in hospital on Sunday.


"Everyone at our Artarmon centre has been deeply saddened by this news," a Little Zak's spokesperson said.

"Our directors have been in contact with the family of the child to convey our sincerest thoughts and condolences and to offer any support we can."

Two of the children remain in hospital, while two others have recovered and been sent home.

Health authorities are working on finding the cause of the child's death.