OLIVIA NEWTON-JOHN has said the rumours of her death have been greatly exaggerated.

Reports in US media claimed the singer, co-star of Grease, had just weeks to live.

The 79 year old revealed in November that she is battling cancer for the third time after a tumour was discovered at the base of her spine.

She has undergone radiation treatment, and is also treating the disease with natural therapies such as the use of cannabis oil.

Newton-John took to Twitter to firmly dismiss the rumours.

In a video statement, she said:

I just want to say that the rumours of my death have been greatly exaggerated, to quote a very famous quote.

I’m doing great, and I want to wish you all the happiest, healthiest 2019 that’s possible.

Thank you all for your wonderful love and support, for me and my Olivia Newton-John Cancer Wellness Centre in Melbourne, Australia.

Happy New Year! Here’s to a wonderful 2019! Love & light, Olivia pic.twitter.com/1Nd2jIcRb1

— Olivia Newton-John (@olivianj) January 3, 2019

A spokesperson for Newton-John had called the rumour “hilarious”.

Newton-John was diagnosed with breast cancer in 1992, but beat the disease. In 2013, she found out that she had cancer in her shoulder.

The entertainer previous told Australian television broadcaster Channel Seven that she is keeping positive.

“There are moments. I’m human. So if I allow myself to go there, I could easily create that, you know, big fear,” she added.

Newton-John, a supporter of cancer charities since her first diagnosis, said she was also hopeful growing cannabis for personal medicinal use would become legal in Australia, like in California.

Additional reporting by AFP