United Kingdom, May 25 -- Meghan McCain's brother has died "suddenly" at the age of 66.

Douglas - the eldest child of the late Senator John McCain - passed away "suddenly" on May 20, and former View host Meghan paid tribute to her "truly wonderful" sibling on May 23.

She posted a shot of Douglas standing beside John, with the caption: "I am deeply saddened to share the news of my brother Doug McCain's sudden passing.

"He was a truly wonderful, joyful man who supported me throughout my life. He brought humour, fun, and great conversation to every room. I will cherish our memories together.

"Our prayers are with his wife, Ashley, and children Caroline and Shepp."

Meghan, 41, did not reveal Douglas' cause of death.

As well as his wife ...