The Italian national broadcaster (RAI) produced numerous cultural documentaries in 1970. Many of these have been digitally remastered into 1080p for the RAIPlay streaming platform or specialized YouTube history channels.
Federico Fellini’s surreal epic was released just before 1970 and heavily utilized the aesthetics of Roman ruins, often associated with the look of Ostia. 2. Archival Documentary or Educational Footage Ostia [1080p] (1970)
There is a notable short film titled , though it was directed by Julian Cole in 1987 . It is a "noir-ish" look at Pasolini's final day. If your date of "1970" is firm, this is unlikely to be the match, but it is the most famous film bearing that exact title. Historical Context of Ostia in 1970 Ostia [1080p] (1970)