Anderson co-founded the progressive rock supergroup with Squire in 1968 and admits the bass player was "a very special part of my life".

The singer says, "He was an amazingly unique bass player - very poetic - and had a wonderful knowledge of harmony. We met at a certain time when music was very open, and I feel blessed to have created some wonderful, adventurous, music with him.

"Chris had such a great sense of humour - he always said he was Darth Vader to my Obi-Wan (Kenobi). I always thought of him as Christopher Robin to my Winnie the Pooh... We travelled a road less travelled and I'm so thankful that he climbed the musical mountains with me. Throughout everything, he was still my brother, and I'm so glad we were able to reconnect recently.

"I saw him in my meditation last night, and he was radiant. My heart goes out to his family and loved ones."

Anderson was kicked out of the group in 2008 when health issues began to impact on his ability to play live.

He was replaced by Benoit David and, subsequently, by Glass Hammer vocalist Jon Davison.

New tributes for Squire have also been posted online from Rush star Geddy Lee, who calls the late rocker an "inspiration", past and present Marillion frontmen Fish and Steve Hogarth, Kiss bass player Gene Simmons and Queen star Brian May, who writes, "Very sad to hear of the passing of Chris Squire. May he rest in peace and happiness, knowing he played a great part in changing Rock for ever. Sincere condolences to his family and friends, and the guys he pioneered wondrous harmony progressive faerie-inspired Rock with."