A woman has been arrested after a 97-year-old dementia sufferer was allegedly abducted from a nursing home in Melbourne, Australia, by a total stranger.

Security footage reportedly showed an "extremely frail" Dimitra Pavlopoulou being wheeled out of Clarinda Manor nursing home by a younger woman at about midday on Saturday (6 December).

She is believed to have then been put in a vehicle before being driven away, leaving her wheelchair behind.

Police issued a public appeal for information after fearing she may come to harm due to her vulnerable condition.

"Dimitra has dementia, speaks limited English, is extremely frail and cannot walk by herself," a Victoria Police spokesperson had said.

Officers were particularly concerned about the impact of the hot weather.

But Pavlopoulou was later found unharmed seven kilometres away at an address in Cheltenham at around 9.30pm.

She was taken to hospital as a precaution.

Detectives are now investigating why she was taken from her nursing home.

A 51-year-old woman from Cheltenham has since been arrested in connection with the alleged abduction and is being questioned by police.

Victoria Police spokesperson Leonie Johnson said the woman is not known to the alleged victim or her family, The Age reported.

A motive for the alleged abduction has not been given.