Simon Cowell leads tributes to Il Divo's Carlos Marin

Simon Cowell has paid tribute to Il Divo's Carlos Marin, who has died aged 53.

The vocalist's passing was announced on Sunday, days after he was reportedly rushed to intensive care in a hospital in Manchester, England with an undisclosed illness. His cause of death has not been confirmed.

After news of Marin's death broke, Simon Cowell, who put the quartet of tenors together in 2003 after a global search, expressed his grief in a statement posted to Instagram.

"I am finding this so difficult to put into words how I feel right now," he wrote. "I am devastated Carlos Marin has passed away. He loved life. He loved performing and always had so much appreciation towards the fans who supported the group from day 1. Rest in peace Carlos. I will miss you."

Marin's bandmates Urs Bühler, David Miller, and Sébastien Izambard, wrote on Twitter, "It is with heavy hearts that we are letting you know that our friend and partner, Carlos Marin, has passed away. He will be missed by his friends, family and fans. There will never be another voice or spirit like Carlos.

"For 17 years the four of us have been on this incredible journey of Il Divo together, and we will miss our dear friend. We hope and pray that his beautiful soul will rest in peace. With Love -- David, Sebastien and Urs."

After being created by Cowell, the group sold more than 30 million copies of their albums worldwide and guest performed on his TV show The X Factor as well as its BBC rival, Strictly Come Dancing.

Strictly judge Bruno Tonioli, who worked with the group as a choreographer, also shared a heartfelt tribute on Twitter.

"Devastated @ildivoofficial @carlosmarin_ passed away," he wrote. "We had the best time putting together the first @ildivoofficial performance 17 yeas (sic) ago great voice great man a true passionate Spirit with wicked sense of humor. We will miss you so sad. B."

TV star Lorraine Kelly, The X Factor contestant Rhydian Roberts, and Britain's Got Talent winners Collabro also offered their condolences.