It was announced on Thursday (11Jun15) that the horror movie star had passed away on Sunday (07Jun15) following three weeks of treatment for heart failure and respiratory problems.

The news prompted an outpouring of tributes online, and Moore - who starred alongside Lee in 1974 Bond movie The Man with the Golden Gun - is among those remembering the revered actor, who was one of his fondest friends.

In a post on Twitter.com, he also extended his sympathies to Lee's widow Birgit, daughter Christina, and son-in-law Juan, writing, "It's terribly when you lose an old friend (sic), and Christopher Lee was one of my oldest. We first met in 1948. Our thoughts are for Lady Lee, Christina and Juan."

Another former co-star, Elijah Wood, who appeared alongside Lee in The Lord of The Rings films, writes, "An extraordinary man and life lead, Sir Christopher Lee. You were an icon, and a towering human being with stories for days. We'll miss you," while another Lord of The Rings castmember, Dominic Monaghan, adds, "So so sorry to hear that Christopher Lee has passed away. He was a fascinating person. Threw a bic pen into a tree in front of me. Legend."

Chloe Grace Moretz, who starred opposite in 2011 movie Hugo and Dark Shadows in 2012, wrote on the microblogging site, "I had the immense pleasure of working with Sir Christopher Lee twice in my career... I'll never forget everything that he taught me and the wonderful conversations we had and how he always helped me keep my head up, my entire heart and prayers go out to him... Rest in peace, it will always be an honour to say I got to know such a beautiful soul, Forever Changed. #SirChristopherLee."

Tributes also came in from across the music industry, recognising Lee's secondary career, which included recording a series of heavy metal albums in recent years.

Black Sabbath rocker Tony Iommi shares, "So sad to hear about the loss of Sir Christopher Lee. The man was truly a legend and such a great inspiration for me and millions of others. His legacy will live on in the hearts of all his fans. My wife Maria and I will remember him with great fondness."

British Prime Minister David Cameron expressed his sadness in a statement which reads, "Saddened to hear of Sir Christopher Lee's death, a titan of Golden Age of Cinema & distinguished WW2 veteran who'll be greatly missed."

Other tributes have also come in from actor Zach Galligan, who worked with Lee on the second Gremlins film, and rocker-turned-photographer Bryan Adams, who shared a portrait he took of the late star.