COMPOSER Sir Peter Maxwell Davies has completed the score for a new opera as he continues to battle cancer.

The 81-year-old, who is based in Orkney, was given six weeks to live in 2013 after being diagnosed with an aggressive form of leukaemia.

After believing he had beaten the disease, Sir Peter was recently given the news that the cancer had returned.

Despite undergoing a new round of chemotherapy, the former Master of the Queen's Music has continued to compose.

"I am so pleased to have finished the children's opera," he said. "I have handed in the 98 pages to the publishers the other day. It was a great relief and quite a moment."

He added: "The treatment I am having is not fun, but the care I have had from the medical staff and support from friends has been wonderful. I'm going to keep writing as long as I can. Music is my life – it is what I do."

Sir Peter is undergoing treatment at University College Hospital in London, travelling every month from his home on the island of Sanday for a week-long round of injections and transfusions.

But in recent weeks, Sir Peter has also been treated at the Balfour Hospital in Kirkwall after suffering "a couple of nasty turns".

He admitted it was "a blow" when told the leukaemia had returned. "I have felt very tired and unwell and it has been a bit of a struggle," he said.

He added: "Now I'm fighting it again. I am going to make the best of my time and write as much as possible."

Sir Peter has drawn from Orcadian mythology for his new opera, The Hogboon, which will be conducted by the internationally acclaimed Sir Simon Rattle.

The Hogboon is a guardian spirit, which can bring either good or ill luck, and is said to dwell in the ancestral mounds that are found across the Orkney Isles.