A pioneering Australian climate scientist and award winning conservation author has allegedly been killed by her own daughter in a nursing home.

Dr Mary E. White, 92, was found dead in her room at the Warrigal aged care complex in Bundanoon, southern New South Wales, on Sunday night.

Her daughter Barbara Mary Eckersley, 67, is due to face Goulburn Local Court today after being charged with the murder of the elderly mother-of-five.

Police were called to the aged care complex at 9.45pm on Sunday. After three days of investigations they arrested Eckersley on Wednesday.

She was charged with murder and refused bail.

Dr White's grandson said after leading a healthy life for more than 85 years, his grandmother had battled dementia in recent years.

'I think it's tragic because she’d been very strong for many years, but that last five years was a very rapid decline,' he told Daily Mail Australia.

'The last time I saw she had gone downhill dramatically from the time before.

'It was really hard on the family, but especially on my aunty Barbara - she was very close to her.'

Dr White and her late husband Bill arrived in Australia in 1955, moving their young family from Zimbabwe.

The paleobotanist authored a series of award winning books on climate change and in 2009 was awarded the Order of Australia for her service to botany as a researcher.

Dr White began studying Botany and Zoology at Cape Town University at the age of just 16.

'Mary was a great woman, she just loved the planet and she was a leader in her field,' her close friend Brett Dolsen said.

'She was a champion of conservation and education programs... and just a really good person too.'

After moving to Australia she quickly became a prominent voice on climate change.

She purchased the Falls Forest Retreat for more than $1million in 2003 and turned much of it into a biodiversity and rainforest sanctuary.

Dr White eventually sold off the greatly reduced farm in 2014 for less than she paid originally.

In a statement, Warrigal nursing homes said they were 'busy working with police and assisting them with their enquiries'.

Police said the cause of Dr White's death is unknown.