From gallifreyone.com:

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The highly acclaimed actor Kevin Stoney has died.

Stoney, who was born in 1921, made striking contributions to Doctor Who, playing the villains Mavic Chen in the epic story The Daleks' Master Plan (1965-66) and Tobias Vaughan in The Invasion pictured (1968).

So impressive was his portrayal of Chen that the Daily Express named the character Villain of the Year.

His final contribution to the series came in 1975, when he played Tyrum in Revenge of the Cybermen.

Stoney also appeared in many other well-known series over the years, including I, Claudius, The Tomorrow People, Bergerac, All Creatures Great and Small and Blake's 7, which was created by Terry Nation.
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The new series has not yet produced a villain who even comes near Tobias Vaughan or Mavic Chen. Kevin Stoney is one of Doctor Who's great guest actors, and gave more than his fair share to the series. I spotted him as a retired alcoholic safecracker in a couple of old Bergerac repeats, on UK Drama recently, and he shone.

Thanks, Mr Stoney.

chuff.x.

He was very good as Tobias Vaughan in The Invasion

That's really sad news. He was wonderful in the Invasion, truly wonderful a real classic British TV villain.

For those of you newish to the series and especially the classic series and recently watching the UKTV Drama re-runs, Kevin Stoney played Tyrum, the elder Vogan in Revenge of the Cybermen.