The 1 Sep 1964 DV announced that producer Jack Laird was preparing two television pilots for Universal Pictures, including The Black Cloak, which was the working title for this picture. At that time, the project was expected to be an hour-long horror series, written for the screen by Barré Lyndon.
       The 30 Nov 1964 and 14 Dec 1964 issues of DV reported that Leslie Nielsen would play the lead in the series, which was expected to be a spin-off of Alfred Hitchcock Presents (CBS/NBC, 20 Oct 1955—20 Jul 1986). Harvey Hart was signed to direct. On 31 Dec 1964, DV indicated that production was underway at Universal Studios in Universal City, CA. The 19 Jan 1965 DV announced a title change to The Uninvited.
       According to 5 Feb 1965 DV, scoring of the television pilot had recently been completed. Over five months later, the 23 Jul 1965 DV noted another title change to Dark Intruder, and stated that Universal had decided to release the project theatrically, after it was turned down as a series by the top three television networks. DV explained that after NBC-TV turned down the pilot, Universal still continued with the production, which was made for $250,000 and released as a fifty-nine minute feature.
       The 21 Jul 1965 Var reported that Dark Intruder opened that day in New York City, but the national release was set for Oct 1965. According to the 22 Jul 1965 NYT review, the picture played on a double-bill with William Castle’s 1965 release, I Saw What You Did (see entry). The review deemed Dark Intruder “a small ‘must’ for mystery shoppers,” noting the excellent plot, and praising Hart for keeping “his yarn simmering crisply and atmospherically.”