The long-time family advocate of seven-year-old Aishwarya Aswath, who tragically died of a bacterial infection after waiting hours to see a doctor at Perth Children’s Hospital, has raised concerns after the resignation of Perth Children's Hospital CEO Aresh Anwar just 12 days before an coronial inquest into the young girl's death.

Suresh Rajan said the evidence of Dr Anwar, the bureaucrat in charge of WA's child health division when Aishwarya died, was critical to the coronial inquest but his resignation meant his participation in the inquest was not guaranteed.

Rajan told Liam Bartlett on 6PR Mornings he hoped Dr Anwar had not been made a scapegoat.

"It's incredibly worrying," Rajan said of the resignation.