Comedian Sean Lock has tragically died from cancer at the age of 58.
A statement from his agent announced the sad news this afternoon.
They said: "It is with great sadness that we have to announce the death of Sean Lock. He died at home from cancer, surrounded by his family."
The statement added: "Sean was one of Britain's finest comedians, his boundless creativity, lightning wit and the absurdist brilliance of his work, marked him out as a unique voice in British comedy.
"Sean was also a cherished husband and father to three children.
"Sean will be sorely missed by all that knew him."
As well as stand up, he made regular appearances on TV shows including QI, The Last Leg, Have I Got News for You, and The Big Fat Quiz of the Year.
Paying tribute, his fellow 8 Out Of 10 Cats Does Countdown team captain Jon Richardson said: "I idolised Sean as a comic long before I became a comedian myself and 10 years working alongside him didn't diminish that in the least. An incredible comic brain and a truly unique voice."
And show host Jimmy Carr added: "Brutal news about Sean Lock today. I loved him. I’m watching clips of him right now - laughing & crying. I’ll miss him so much."
Meanwhile Channel 4 said: "Incredibly sad to learn of the loss of one of our greatest comedians, Sean Lock. A much loved part of the C4 family he’s played a huge role on the channel for over 2 decades, and we’ll miss him. Our thoughts are with his family and friends."
The channel has announced that tomorrow night (Thursday, 19 August), it will be airing the stand-up special Sean Lock: Keep it Light at 10PM, followed at 11PM by a classic episode of 8 out of 10 Cats Does Countdown. All 4 will be highlighting a collection of Sean’s much-loved TV appearances including 8 out of 10 Cats Does Countdown.
Many of Sean's co-stars and fellow comics have been quick to pay tribute.
Comedian Bill Bailey said: "It's heartbreaking to lose my dearest friend Sean Lock, he was a true original, a wonderful comic."
Ricky Gervais added: "Such sad news. RIP the great Sean Lock. One of the funniest, most influential comedians of a generation. A lovely man."
And Richard Osman tweeted: "Over 15 years producing 8 Out Of 10 Cats, Sean Lock made me laugh so much and so often. A unique and brilliant comic voice. Love to his family and his many friends."