Husband accused of murdering elderly wife after she collapsed

An 85-year-old Perth man has been charged with murdering his elderly wife, who had been suffering from advanced dementia.

Nancy Barclay, 83, had a medical episode and collapsed inside her Brompton Place home in Alexander Heights yesterday morning, police said.

Her husband, Harold Barclay, is now accused of killing his wife in the moments after she collapsed.

Police sources have told 9NEWS that prosecutors will allege Mr Barclay believed he was "putting her (Mrs Barclay) out of her misery".

Today Mr Barclay was heard by the Perth Magistrates court via telephone in a bedside hearing.

The cancer sufferer remains under police watch at Royal Perth Hospital, where he is being observed for mental health concerns.

The 85-year-old's voice trembled when he was asked by the magistrate whether he understood the charge.

"I do understand the charge," he said.

A close family friend has told 9NEWS that Mr Barclay had recently elected to stop his cancer treatment. 

Neighbours earlier said the couple had been married for 63 years and that Mr Barclay appeared to be a loving husband.

Friends said the accused and his three children had been looking in to options for moving Mrs Barclay into a care facility.

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