Stephen Fry said actor and comedian John Sessions, who has died aged 67, was “as warm, vulnerable, lovable and loving as anyone can be”.
The star, who enjoyed a career across TV, film and the stage, died on Monday.
He was known for regular appearances on shows such as Whose Line Is It Anyway?, QI and Have I Got News For You, and for his work on Spitting Image.
Fry said he is “already missing Johnny Sessions dreadfully” in a post on Twitter.
He added: “As warm, vulnerable, lovable and loving as anyone can be.
“And so so much talent. He could make me laugh until I was sick and dizzy with pleasure and exhaustion.
“I can’t bear that he’s gone.”
Sessions’ agent Alex Irwin said in a statement on Tuesday: “It is with great sadness we can confirm that on Monday, the actor John Sessions died at his home in south London.
“He will be hugely missed.”
Panel show QI said in a tweet: “John Sessions was a panellist on QI’s first ever episode: Series A, Episode One, ‘Adam’.
“His incredible wit and encyclopaedic knowledge played a huge part in the show’s history and everyone at QI is deeply saddened to learn of his passing.”
Broadcaster Danny Baker shared a poster for radio series Beachcomber… By The Way, and wrote on Twitter: “Shocked to hear that John Sessions has died at 67.
“Terrific company always and a true talent. His roles at the heart of this, my favourite radio series, have given endless pleasure to me and will continue to do so always. Travel easy, chum.”
Actor and writer Robert Webb paid tribute to Sessions and fellow comedian Bobby Ball, whose death was announced at the weekend.
“Two very different performers who both absolutely inspired and delighted me at different times. Lovely, funny men,” he said.
The Crown star Jason Watkins said it was “terrible news” about Sessions’ death.
He tweeted: “He was unique. A genius, who gave us his huge intellect, fascination in people – above all the blinding sense of humour – scissor like wit and danger too.”
BBC Radio 5 Live presenter Nicky Campbell also paid tribute to Sessions.
“One time when I was interviewing John Sessions on late night Radio One he did an impression of Bryan Ferry as a Glasgow drunk,” he tweeted.
“Rarely have I laughed as much. #RIPJohnSessions.”
Actor Chris O’Dowd said Sessions “in various forms, has made me laugh my arse off for 30 years”.
The IT Crowd star added: “I was delighted to lure him into joining us on Moone Boy for a short while and he was glorious.
“The world may move a little slower today, without his dynamo of a mind to propel it. Thank you John.”
The BBC also paid tribute to the late comedian.
“We’re saddened to hear of the death of actor and comedian John Sessions,” a tweet from the corporation’s press office said.
Blur musician Graham Coxon said: “John sessions… was mega bright and funny.. that’s a great shame. RIP.”
The Scotland-born actor’s big screen credits included Sir Kenneth Branagh’s Henry V, The Good Shepherd, The Merchant Of Venice and The Bounty.
He was also known for his surreal performances on his one-man TV shows.
His TV acting credits included Stella Street, Victoria and The Loch.