United Kingdom, June 5 -- James Marsters has paid a heartfelt tribute to Anthony Head.

The Buffy the Vampire Slayer actor "passed away peacefully of complications due to pneumonia", aged 72, and James has now paid a glowing tribute to his former co-star.

The 63-year-old actor - who played Spike in Buffy the Vampire Slayer and its spin-off show, Angel - wrote on Instagram: "There's a hole in the World. Anthony Head has passed on from us. He was an unflaggingly kind and steady presence on the set of Buffy, and the best actor in the cast. He was the best of us. I was lucky to have known, and learned from him. He left the world a better place for his presence. Thank you Tony for all you gave. (sic)"

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