The Oblong Box (1969)

Julian (Vincent Price) hides his horrendously disfigured brother, Sir Edward Markham (Alister Williamson), in a tower where he is kept in chains. Anxious for freedom, Edward fakes his death with the aid of an immoral attorney, Trench (Peter Arne), and a pill that puts him into a catatonic state. But the escape plan takes a treacherous turn when Julian unwittingly buries his brother alive -- and he's later unearthed by grave robbers under the employ of malevolent Dr. Neuhardt (Christopher Lee).