David McCallum's accent comes and goes; it goes from undetermined, almost Slavic accent to full-blown British, punctuated by some almost correct French R sounds.
Intentionally or not, David McCallum, with his big glasses and mod haircut, is almost the "spitting image" of International Rescue's super-smart member Brains from the 1960s British adventure series Thunderbirds (1965), in which all of the cast members were actually oversized marionettes.