[5] He moved into Kvaran's home,[6] and then in 1907 the Society built an Experimental House for him to provide maximally controlled conditions for observing him.
[7] After a visit to the Westman Islands in September 1907, according to Spiritualists, he was increasingly troubled by poltergeist phenomena and members of the Society had to spend the night in the room.
[12] Allegedly a control personality emerged who claimed to be Konráð Gíslason, Indriði's grandfather's brother, who had been a professor of Icelandic language at the University of Copenhagen.
[15] Proponents defend the genuineness of the phenomena, saying that no equipment capable of producing the lights was available in Reykjavík, and the Kvarans attested that Indriði had only a single footlocker with no lock, and they and others searched him and kept him under observation.
[18] Spiritualists considered Indriði primarily a physical medium, and say he correctly reported pieces of information, such as a big fire in Copenhagen.
[19][20] In winter 1906-07, the Society held "apport séances" in Kvaran's home during which Indriði allegedly materialized objects from all over Reykjavík.
[23] After Indriði's visit to the Westman Islands in September 1907, Spiritualists say he was plagued by poltergeist and levitation phenomena that he and his controls attributed to a man named Jón, whom he had seen and made insulting remarks about.
[25] According to Haraldur Níelsson's account to the Second International Congress for Psychical Research, Jón was thought to be a recent suicide.
Fjallkonen condemned a supposed "healing operation" in which an individual died after Indriði attempted to cure him of cancer, as "outrageous" and an "offense".
Kvaren and other proponents responded by saying the accusations were religiously motivated and untrue, and claimed that Indriði had genuine paranormal abilities.
[32] Newspapers of the time continued to publish scathing critiques of Indriði, describing Spiritualism as "ludicrous ghost-religion" and "nonsensical, ridiculous vanity".