An investigation has been launched into how a child died after being hospitalised during a Sydney gastro outbreak, while another remains in hospital.
Six children, aged 11 months to four years, from Little Zak's Artarmon were struck down with the virus in the past week.
Four were hospitalised with the illness with three since being discharged, NSW Health said on Thursday.
A seventh child, who also attended Little Zak's, died in hospital on Sunday.
However, NSW health authorities say they're "pretty confident" the death was not related to the illness and it's believed the child did not contract the virus at all.
Dr Michael Staff from NSW Health confirmed the department is investigating what caused the child's death.
"Because the child presented with different symptoms ... we're in the process of actually working out what the cause of illness is with some expert paediatricians," Dr Staff told Seven Network on Thursday.
A Little Zak's spokesperson said everybody at the Artarmon centre was deeply saddened by the news.
"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," they said.
Little Zak's confirmed a letter had been sent out to parents on Wednesday afternoon explaining the situation.
However, several parents were angry they had not been informed sooner, and some had decided to keep their children at home in the following days, according to the Seven Network.
