Kiwi mum and son found dead in Sydney

Police are investigating how a Kiwi woman and her young son died after their bodies were found inside a unit in Sydney's east yesterday.

Emergency services found the pair - named by various media as Stacey Docherty and 4-year-old Seth - at the Hillsdale residence after Ms Docherty's former partner reportedly raised the alarm about their welfare.

Police are looking into whether their deaths were the result of a murder-suicide or whether a third person was involved.

"It is early stages in the investigation," Superintendent Leanne McCusker said.

Fairfax Media reports "rambling ... barely decipherable words" were written all over the walls of the unit in blood when emergency services discovered the pair's bodies, around 1.20pm.

Ms Docherty listed her job on Facebook as a nursing manager from Christchurch, and filled her social media feed with photos of her son.