The Hobbit star told of the relief he felt after his mother May lost her lengthy battle against the disease last year - and has called for more government action on Alzheimer's treatment.

The NI film and TV star was filming overseas when his mum passed away in June - almost a decade after she developed the debilitating condition.

"She went through all the stages, it's a degenerate and progressive disease and it is important to remember it is a disease," he added.

"She went through those stages of just forgetfulness and then flitting between fantasy and reality, the present and the past, rage and confusion and it got to a state where she could no longer live at home. Of course, she was looked after very well in a couple of homes - the Brook in Coleraine and Madelayne Court in Portstewart.

"And then finally she was released to great relief really last summer."

Nesbitt, who is chancellor of the University of Ulster, was speaking on Monday at the major conference in Belfast where hundreds of the world's leading dementia doctors and scientists had gathered to discuss the latest research developments.

Nesbitt told the audience that the government must make Alzheimer's research a new priority.

He said that the only thing that will tackle the disease is a treatment.

Alzheimer's Research UK is supporting research projects worth over £20 million at universities, including the University of Ulster.

Nesbitt continued: "It's a tale that more and more people are being able to tell because you know with an ageing population, the Alzheimer's crisis is becoming almost epidemic.

"You know there are 820,000 sufferers in the UK, by 2021 that could be over a million. The only way it can be dealt with is treatment, the only way we can get new treatment is through research, the only way we can get research is through funding.

"So, I am principally here to raise awareness for it and to try and make sure that we can continue to persuade government at a national level and on a local level that we need funding."