Former Scotland international Doddie Weir has revealed he is battling motor neurone disease.
The 46-year-old retired lock says he has decided to announce his diagnosis to raise awareness of the condition.
He is now joining forces with researchers to help tackle the degenerative condition, which occurs when specialist nerve cells in the brain and spinal cord stop functioning properly.
Edinburgh-born Weir won 61 caps for Scotland and was part of the squad which won the 1999 Five Nations title. The 6ft 6ins forward was also called up for the British and Irish Lions' 1997 tour of South Africa.
Weir - who is supporting Global MND Awareness Day which takes place on Wednesday - said: "Over the past few months a number of friends and family have raised concerns surrounding my health.
"I think then, that on this day set to help raise awareness of the condition, I should confirm that I too have motor neurone disease. I should like to take this opportunity to thank the National Health Service in recognising then diagnosing this, as yet, incurable disease.
"I am currently on holiday in New Zealand with [wife] Kathy and the boys and when we return, I will devote my time towards assisting research and raising awareness and funds to help support fellow sufferers.
"There are plans in place to create a charitable foundation to help in any way we can and we will share these details with you after our family trip."
Weir has given his backing to researchers at the Euan MacDonald Centre at the University of Edinburgh in their quest to better understand the disease in the hope that it will eventually lead to new therapies.
The former second-row follows in the footsteps of South Africa's World Cup winning scrum-half Joost van der Westhuizen, who visited the centre in 2013 to share knowledge and expertise. Van der Westhuizen died in February after losing his battle with MND.
Professor Siddharthan Chandran, director of the Euan MacDonald Centre for motor neurone disease research, said: "We are immensely grateful to Doddie for his support at this difficult time for him and his family.
"Working in partnership with other researchers and charities such as MND Scotland, our goal is to bring forward the day when there are effective treatments for this very tough condition."
After learning the news, the Scottish Rugby Union has vowed to do all it can to support the stricken former Dark Blues hero.
In a tweet, Murrayfield chiefs said: "All our thoughts are with Doddie & family. He represented Scotland for 10 yrs & we will look to support him & his charity initiative."