 Christopher Plummer (I) (qv) was originally considered for the  lead role, but dropped out to star in  _Sound of Music, The (1965)_ (qv). The role was then offered to  Richard Harris (I) (qv) who also refused it. Harris later rued his  decision, commenting to Sean Connery (qv) that he "turned down  The Ipcress File but did _Caprice (1967)_ (qv) with  Doris Day (I) (qv)".