Addison Cresswell, an influential comedy agent and producer, who helped along the careers of noted British comedians like Jonathan Ross, Jack Dee and Michael McIntyre among others, has passed away. Cresswell was 53. His management company Off The Curb, released a statement Monday, saying that the producer had "passed away in his sleep at home".

Jonathan Ross, BFI Fest
Cresswell famously managed Jonathan Ross' 2006 deal with the BBC.

The statement said Cresswell be would be "fondly remembered as a devoted mentor, a dear friend and an unforgettable character". Cresswell reportedly had a heart attack on Monday morning, BBC News reports.

Since the announcement, condolences have started flooding in. Comedian Dara O’Briain was among the first to pay his respects on Twitter, saying: “Deeply saddened and shocked by the loss of Addison Creswell. A good friend and a tremendous character; he will leave an unfillable void."

Dara O'Briain
Dara O'Brian was one of the first to pay his respects via Twitter.

Stephen Fry also tweeted his own message today, saying: “Oh goodness, I’ve just heard about Addison Cresswell a larger than life impresario manager. My deepest sympathy to all his family & friends”

Working mostly behind the scenes, Cresswell was one of the most influential figures in British comedy. In 2006, he brokered Jonathan Ross's £18m three-year deal with the BBC. He also had quite a few achievements as a producer, including working on Alan Carr’s Chatty Man and Live at the Apollo though his Open Mike company.

From entertainments officer at Brighton Polytechnic, Cresswell went on to manage some of the biggest names in comedy, including Jo Brand and Lee Evans, but his very first client was the poet Joe Hegley, when Cresswell started his business from his kitchen table. Cresswell's spokesman said he was "survived by his beloved wife Shelley, his dogs Bonnie and Nessie and many, many pet fish".