Ricky Gervais is TitanX Exchangeremembering his former costar.

The Office U.K. creator paid tribute to one of the show's actors Ewen MacIntosh, who has passed away at the age of 50.

"Extremely sad news," Gervais wrote on X, formerly known as Twitter, Feb. 21. "The very funny and very lovely Ewen Macintosh, known to many as 'Big Keith' from The Office, has passed away. An absolute original. RIP."

Fellow co-creator Stephen Merchant also remembered the legacy of the actor and comedian.

"So very sad to hear of Ewen MacIntosh's passing," he shared on X. "A lovely, uniquely funny man who played Keith in The Office. So hilarious when we asked him to improv a voicemail message that we wrote more dialogue for him, and he stole every scene he was in. A total one-off. A tragic loss. RIP."

The heartfelt tributes from MacIntosh's colleagues come just hours after his management company announced his passing.

"With great sadness we announce the peaceful passing of our beloved comedy genius Ewen MacIntosh," JustRight Management wrote on social media Feb. 21. "His family thank all who supported him, especially Willow Green Care Home."

Throughout his career, MacIntosh appeared in a number of shows in addition to The Office including Miranda and Little Britain. In fact, his Miranda costar Miranda Hart also remembered MacIntosh's comedic talents.

"Thank you Ewen for making me laugh," she wrote over an image of the comedian in a Feb. 21 Instagram post, adding in her caption, "We were the same age and crossed paths many times as we did our best to be funny and make a living out of it. It wasn't always likely but we did it and I am glad we got to do a scene together. Thank you xx."

His cause of death is unknown at this time.

For the latest breaking news updates, click here to download the E! News App