John le Carré, best known as the author of some of the most well-known spy thrillers in the world, has died at the age of 89.

Originally an intelligence officer himself, le Carré wrote his first three novels - 'Call for the Dead', 'A Murder of Quality', and 'The Spy Who Came in from the Cold' - while he was still in MI6 before retiring to become a full-time writer. The recurring character of several of his novels, George Smiley, was a direct antidote to James Bond. The character has seen been portrayed on screen by Alec Guinness in the TV miniseries of the '80s, and more recently, Gary Oldman.

Florence Pugh posted an emotional tribute to le Carré, having starred in a new adaptation of 'The Little Drummer Girl' previously. "I remember sitting down next to him at dinner and after a while of back and forth, realising that we were both trying to figure each other out," she wrote.

"Sizing one another up, testing and teasing each other constantly. Until, I called him an old fart. I watched his eyes light up with glee and we both cackled until we cried. He peered at me over his glass and giggled, 'I think we’re going to get along just fine.' We knew a magical friendship had arrived."

Gary Oldman, in a statement released to media, described how le Carré's "characters were drawn deftly and deeply, nuances too many to count, and for me, inhabiting George Smiley remains one of the highpoints of my life."

"I got to know David a little bit, over conversations, lunches, and his visit to the set. Amazingly, he was always at the other end of the phone if we had a question, or needed a line or to confirm if a character might say something specific. He always had immediate answers. He was generous with his creativity, and always a true gentleman."

Meanwhile, author Stephen King, the band Massive Attack, actors Stephen Fry and Hugh Laurie, and many others posted their tributes and thoughts via Twitter.

Here's a few.