George Harrison insisted he was "feeling fine" yesterday after enduring his fourth health scare in as many years. The former Beatle has undergone a course of radiotherapy at a cancer clinic in Switzerland.

There had been speculation that he was suffering from a brain tumour but neither the clinic nor his lawyer would confirm the details of his illness. The London solicitor Nicholas Valner confirmed he had been treated at the oncology institute at the San Giovanni Hospital in Bellinzona last month.

Displaying the optimism that has characterised his previous bouts of cancer, Harrison said yesterday: "I am feeling fine ...Please don't worry."

The 58-year-old musician's treatment was overseen by the leading cancer specialist Dr Franco Cavalli. "Mr George Harrison was referred to the hospital to undergo a course of radiotherapy. He successfully completed the course more than a month ago and we foresee no need for further treatment here," he said.

Harrison has had treatment for cancer on two previous occasions, the most recent being in March when a cancerous growth was removed from one of his lungs. He was operated on at the Mayo Clinic in Rochester, Minnesota, before flying to Italy to recuperate. At the time, friends said he had made an excellent recovery and he joked that he had "no plans" to die.

He had surgery for throat cancer only four years earlier and then came close to losing his life in 1999 when an intruder, Michael Abram, stabbed him after a break-in at his home in Henley-on-Thames, Oxfordshire. Abram was sentenced to be detained indefinitely at a secure hospital after a jury decided he was insane.

Speaking earlier this year Harrison observed: "I had a little throat cancer. I had a piece of my lung removed in 1997. And then I was almost murdered.

"But I seem to feel stronger. I don't smoke any more. I'm a little more short of breath than I used to be, so I don't see myself on stage lasting a full 14 rounds."