Cricket veteran Sir Ian Botham has said the terrible thing about dementia is that “you watch someone die twice over”.

The former England all-rounder has spoken about the death of his father, Les, in 2005 following a lengthy period living with dementia.

“Unless you’ve watched a loved one being ravaged by this disease, you can’t understand how horrendous it is,” he told the UK’s Daily Telegraph.

Botham did not visit his father for the last six months of his life, saying: “I didn’t want my memory of him to be distorted by the illness that robbed him of himself.”

He said his father was “as near to a zombie as you can imagine” by the end, and had no idea who his mother was.

Botham said his father would have been “mortified” if he had known the “humiliation” that lay ahead.

The sportsman recalled when he initially began to realise something was not quite right with his father when the pair were at a golf club.

“The man taught me to play golf when I was three, but he had forgotten how to play it,” he said.

Botham described watching his father deteriorate as “appalling”, and said the illness made his father become violent and added that he required sedation.

He said the his mother “aged years” and would cry after every visit to see his father.

“That’s the terrible thing about dementia – you watch someone die twice over,” he said.