Green’s Dictionary of Slang

peek n.

[SE peek]

1. (US) a peephole, e.g. in a brothel.

[US](con. 1949) J.G. Dunne True Confessions (1979) 112: Never took off that white suit while they were doing him. I used to watch him through the peek.
[US]J. Ellroy Widespread Panic 20: ‘He lured me to a hotel with a wall peek’.

2. (UK prison) an observation cell, into which prisoners are placed if, for instance, they have smashed up their cells or shown other signs of instability.

[UK]Partridge DSUE (8th edn) 864: [...] mid-C.20.

In compounds

peek freak (n.) [freak n.1 (5)]

a homosexual voyeur who watches two other men during sex.

[US]Lavender Lex. n.p.: peek freak:–A person who receives sexual gratification, by watching others in the sex act. This should not be confused with those who are sexually aroused by watching a sex act. Also policemen who spy indiscriminately on persons in public toilets. Also any person who goes into gay bars and restaurants for the purpose of observing gay activity for perverse reasons; A voyeur.
[US]J.P. Stanley ‘Homosexual Sl.’ in AS XLV:1/2 58: peek freak n One who enjoys watching others during intercourse.
[adult film title] Peek Freak.
peek show (n.)

a live sex show.

Nick posting 30 Jun. at Melbourne IndyMedia 🌐 You are right the film shouldn’t be banned. There is probably a peek show next the cinema offering sex shows and alike.