Actor Alan Rickman poses for a photo before a special family fundraising evening hosted by author J.K. Rowling in aid of her children's charity, Lumos, at the "Warner Bros. Studio - The Making of Harry Potter in Hertfordfshire", in London, in this November 9, 2013 file photograph. [Photo/Agencies]

Daniel Radcliffe, who starred alongside Rickman as Harry Potter, said he was "undoubtedly one of the greatest actors I will ever work with".

"Film sets and theatre stages are all far poorer for the loss of this great actor and man," he said.

Harry Potter author JK Rowling tweeted: "There are no words to express how shocked and devastated I am to hear of Alan Rickman's death. He was a magnificent actor and a wonderful man,"

The Guardian newspaper said Rickman was always politically active with the left-wing Labour Party and his wife, Rima Horton, his partner of more than 50 years whom he married in secret last year, had been a Labour councillor in London.

"Brilliant actor, deeply principled man. My heart goes out to Rima and his family," Ed Miliband, Labour's former leader said on Twitter.