Lupin III: Pilot Film
Two years after the birth of the manga a pilot film was realized. It was a brief film of only 15 minutes that had the purpose of assay the response to a possible future anime realization of Lupin III. The pilot opens with a challenge call from Lupin to Zenigata from a public phone.
A remastered version was realised in 1978, re-photographed in cinemascope and re-dubbed for being screened in cinema before of 1st movie [The Secret of Mamo].
(Source: AniDB)