Green’s Dictionary of Slang

peter n.⁶

also Peter File

[pun on ‘paedo/peter phile’]

(N.Z. prison) a child molester.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 138/2: peter n. 4 a child molester [...] Peter File n. a name given to a child molester.