Published Sunday, 15 July 2012
The 84year-old revealed last year he had been diagnosed with bladder cancer and was undergoing treatment in a bid to beat the disease.
Doctors reportedly told Williams recently that there is nothing more they can do for him in his health battle, and the Sunday Express newspaper reports the star has returned to his "spiritual home" of Branson, Missouri to spend time with his wife Debbie and his three children from a previous marriage.
A friend tells the publication: "They are all desperately sad to see their father suffer but he has told them all not to cry for him and remember him when he has gone through the music he has loved all his life.
"Sadly, a stent inserted in his bladder became infected. He has been in constant pain and lost all his hair due to chemotherapy and radiation treatments. There was nothing more his doctors could do for him."