Stars of the Harry Potter films have been paying tribute to Alan Rickman after learning of his death yesterday (Jan 14).

The London-born actor, who died aged 69 after suffering from cancer, enthralled audiences as Professor Snape, spending 10 years filming the series at Leavesden.

Daniel Radcliffe called him "undoubtedly one of the greatest actors I will ever work with" in a post on his Google+ account and spoke of his continued support and encouragement. He added: "I will carry the lessons he taught me for the rest of my life and career."

Read his full post below.

Watford Observer:

Emma Watson wrote on her Facebook page: “I’m very sad to hear about Alan today. I feel so lucky to have worked and spent time with such a special man and actor. I’ll really miss our conversations. RIP Alan. We love you.”

JK Rowling, the author of the Harry Potter series, expressed her condolences on Twitter.

Rickman's death came just days after the birthday of his Harry Potter character Snape on January 9.

The wizarding professor's famous lines included: “I can teach you how to bottle fame, brew glory, even put a stopper on death.”

And fans have been paying tribute to him using his final line on the films "Always", from Harry Potter and the Deathly Hallows, in which the professor reveals his undying affections for Harry's mother, Lily. 

His passing will perhaps cast a shadow over the 15th anniversary celebrations of the first film The Philosopher's Stone which are planned for later this year at Leavesden. See details here.