Sir Sam Neill was "patient zero" for a new cancer treatment which led to him being given the "all clear" four years after his diagnosis.

The Jurassic Park star, 78, recently revealed he is now cancer-free after spending the last few years battling stage 3 lymphoma and he's now credited an innovative new treatment called CAR-T therapy with saving his life after the chemotherapy sessions which had been keeping him alive stopped working.

In a post on Instagram, he shared a video of a TV interview in which he talked about being free of cancer and explained: "Thanks to science I am cancer free. I don't really like talking about me and cancer. Makes me uncomfortable.

"But here is the background to the above and the journey of how I arrived here."

Sam went on to add: "I had been on chemotherapy for some years, but the chemo for my particular lymphoma was starting to not work anymore.

"Things were getting a little … serious . We were all at a bit of a loss. Then out of the blue I found myself on a clinical trial . This for a new type of CAR-T therapy, that was aimed at my particular lymphoma. All brand new.

"We were sailing into uncharted waters. No one knew exactly what we could expect. I think I was first out of the block and I think the term for me was 'Patient Zero'. From now on please address me as Mr Zero!"

Sam added: "This turned out to be great good fortune for me. And last week I had all the scans etc, and I am pleased, indeed delighted to say that there is no cancer in my body. All clear. We are all amazed."

The actor then went on to thank his doctors in Australia for all their hard work, writing: "So now first of all I want to thank Professor Miles Prince and his wonderful team in Melbourne. As well as Dr Orly Lavee and hers, in Sydney.

"And I am still processing this miraculous information. But of course it is not a miracle, it is science at its best. And a lot of people who care deeply about their work and their patients. I am immensely grateful."

Sam concluded his post by declaring he is now pushing for CAR-T therapies to be rolled out to all those that need it, adding: "Now. Here's why I'm posting this. Treatments like this - CAR-T therapies and others coming through in a rapidly changing medical world - I hope to be available to everyone who needs them in Australia NZ (and worldwide ).

"This is what I am advocating , along with The Snowdome Foundation, to push for exactly that."