Doctor Alex George has thanked fans for the outpouring of support after the death of his younger brother Llyr.

The 30-year-old announced yesterday that Llyr had passed away after a battle with mental health issues, just a month before he was due to follow in his big brother's footsteps by starting medical school.

"Thank you for all the messages of kindness here and to my phone," George wrote on Instagram this morning.

"I am incredibly grateful of the support and it means so much. I am sorry that I can't reply yet.

"I need to try and process what has happened, somehow."

Paying tribute to Llyr yesterday, Alex described him as "the kindest and most caring soul".