Bearded, heavy-set New Zealand-born character actor with a booming voice, who went to England to study at the Royal Academy of Dramatic Art. After repertory experience, he had notable stage appearances with the National Theatre Company (of which he was a founder member) and the Mermaid Theatre, invariably in Shakespearean parts. His portrayals of Balthasar in 'Much Ado About Nothing' (1965) and Sebastian in 'The Tempest' (1970) were particularly well received. He also played Doolittle during a European tour of 'My Fair Lady'.

During the 1970's, Purchase made frequent guest appearances on such television series as I, Claudius (1976), Rumpole of the Bailey (1978), Blake'in Yedilisi (1978), and (famously larger-than-life) in the Doctor Who (1963) episode 'The Pirate Planet'. His role was that of a cybernetically-enhanced pirate captain, complete with a robotic parrot. Among other notable TV performances were his Duke of Buckingham in The First Churchills (1969) and his Earl of Northumberland in the BBC production of 'Henry IV'. He continued to alternate television with appearances on the stage. During the production of 'The Last Confession' (starring David Suchet) in May 2007, Purchase, playing a cardinal, became ill and died aged 69 in June 2008.