An elderly Australian woman lay dead in her home for around seven years before her body was found, an inquest was told on Thursday.

Police found Natalie Wood's body in her Sydney home in July 2011. She is believed to have died in 2004.

Police said she may have died after a fall, but the amount of time since her death made it "forensically almost impossible" to determine her death.

Ms Wood has been dubbed "the woman Sydney forgot" by local media.

She was born in 1924.

A police officer told the Glebe Coroners Court that Ms Wood "kept to herself... it got to a point she answered the door with a special knock".

Rings and valuables inside the house had not been touched, although there was no TV, fridge, mattress or purse inside.

There were cobwebs throughout the house, and a tree growing outside had spread into the upstairs of her home.

Ms Wood's sister-in-law, Enid Davis, said she last saw Ms Wood from a bus window in January 2004.

"There was no reason [we stopped talking] other than my husband had dementia and got very sick," she said.

Ms Davis and some of Ms Wood's cousins are seeking to claim her estate.