Peppered with sleazy re-enactments and unflattering close-ups, “Voyeur” — a squirmy documentary about the celebrated journalist Gay Talese’s infamous investigation of a perverted motel owner — leaves you with an urgent need to take a shower.

Had you done so in the Colorado establishment owned by Gerald Foos some time between 1966 and 1990, your host might have been peering through a ceiling vent, taking copious notes on your ablutions. An obsessive peeper who enjoyed decades of onanistic pleasure at his oblivious guests’ expense, Mr. Foos shared his prurient interests and diaries with Mr. Talese, who documented them for The New Yorker in 2016. A poorly reviewed book followed, only to be briefly disavowed by Mr. Talese after The Washington Post unearthed serious discrepancies in Mr. Foos’s recollections.

Filled with unasked questions and unverified assertions, “Voyeur” is a sad, strange tale of two men whose similarities of taste and temperament — including extreme ego, unbridled nosiness and a penchant for the lurid — are its real subject. Chronicling the literary debacle and the decades-long relationship that preceded it, the directors Myles Kane and Josh Koury dance from the memorabilia-crammed basement in Mr. Talese’s Manhattan brownstone to the cluttered living-room in a Denver suburb where Mr. Foos holds court.