Kate Bush has shared that one of the swimmers who went missing on Christmas Day was “one of (her) dearest friends.”

The Running Up That Hill singer used her official website to pay tribute to her friend Matthew Upham, who remains missing after taking a swim off the coast of Devon, England, on Christmas Day.

"Matthew was one of my very dearest friends. I had known him for thirty years," she began. "He was one of those people who left a mark on everyone he met. He was incredibly kind, thoughtful, and lived life to the fullest. He was also so much fun."

The 67-year-old added, "His family are heartbroken, and along with many of his friends, so am I."

Bush also highlighted that Upham was a “very strong” swimmer with a deep respect for the sea.

“It is so tragic that he went missing in this way,” the Cloudbusting singer said. “The world has lost someone truly special. Thank you, Matthew, for being one of the best friends anyone could hope for.”

Emergency services were called to Budleigh Salterton in Devon at around 10:25 a.m. on December 25 after antiques dealer Upham, 63, and a man in his 40s could not be located. The coastguard concluded its search and rescue operation at 5 p.m. that same day.

Over the weekend, Upham’s family posted a statement on his Instagram page, saying he “is deeply loved and will be forever missed.”

“We want to express our heartfelt thanks to the emergency services who responded, especially the RNLI (Royal National Lifeboat Institution) and the coastguard, for their dedication, professionalism, and tireless efforts during this incredibly difficult time. We are profoundly grateful for their compassion and support,” they added.