AC/DC guitarist Malcolm Young diagnosed with dementia

Malcolm Young (left), alongside bandmates Brian Johnson and Angus Young. Credit: CP CANADIAN PRESS/The Canadian Press/Press Association Images

The family of AC/DC guitarist Malcolm Young have announced that he is suffering from dementia.

"Malcolm is suffering from dementia and the family thanks you for respecting their privacy," they said in a statement.

A source at the Sydney Morning Herald said the star was now in full-time care at a nursing home in the city.

The source said Young's illness was so bad that he could no longer remember how to play AC/DC songs.

The 61-year-old founded the seminal Australian rock band in 1973 with brother Angus, with the group going on to sell over 200 million albums worldwide.

Earlier this year the band had announced that illness meant Young would not be joining them in support of new album Rock or Bust.

His nephew Stevie Young will perform on the album in Malcolm's place and join the band on a forthcoming world tour.

Although brother Angus may have garnered more attention as the shorts-wearing lead guitarist, he described Malcolm's "sheer power" as "much more unique".

He wrote in Guitar World: "Mal is really a great all-around guitarist. I know it says "rhythm guitar" on the album jacket, but if he sits down to play a solo, he can do it better than me.