Jurassic Park star Sam Neill has revealed he has been undergoing treatment for stage three blood cancer.

The 75-year-old actor told The Guardian that writing his memoir gave him a “reason to live” following the diagnosis.

He said he started writing the book as a way to keep busy while receiving treatment last year.

“I realised it was actually sort of giving me a reason to live,” Neill said.

“I would go to bed thinking: ‘I’ll write about that tomorrow… that will entertain me.’

“And so it was a lifesaver really, because I couldn’t have gone through that with nothing to do, you know.”

Neill, from New Zealand, said he first experienced swollen glands during publicity for Jurassic World: Dominion in March last year before being diagnosed with angioimmunoblastic T-cell lymphoma – a rare type of non-Hodgkin lymphoma.

More from Ents & Arts

His book also reportedly discusses his experience with chemotherapy, which initially started to fail, before he was given a new chemotherapy drug that he will take monthly for the rest of his life – despite now being cancer-free.

Neil told The Guardian: “I can’t pretend that the last year hasn’t had its dark moments. But those dark moments throw the light into sharp relief, you know, and have made me grateful for every day and immensely grateful for all my friends.

“Just pleased to be alive.”

Neill starred as Major Chester Campbell in the hit BBC series Peaky Blinders and reprised his role as Alan Grant in the blockbuster Jurassic Park franchise last year.

His memoir, Did I Ever Tell You This?, will be published on 21 March.