Nielsen was born in Copenhagen, Denmark. He travelled in Europe giving séances and claimed to be able to produce spirit materializations. He was discovered to be a fraud in Oslo, 1922 and in 1932. The committee from the Kristiania University in Norway in a séance discovered that the ectoplasm of Nielsen was fake. The psychical researcher Harry Price sat with Nielsen in Copenhagen with "unsatisfactory results." Nielsen was also caught hiding his ectoplasm in his rectum. In 1932, Johs Carstensen the leader of Nielsen's spiritualist circle wrote a pamphlet which exposed his tricks. Nielsen continued to work as a medium until his death but was never considered credible again by people outside of his small circle of influence. He published the book Solid Proofs of Survival in 1950.
- Einer Nielsen (1894-1965)
- Paul Kurtz. (1985). A Skeptic's Handbook of Parapsychology. Prometheus Books. p. 475. ISBN 978-0879753009
- Lewis Spence. (2003). Encyclopedia of Occultism & Parapsychology. Kessinger Publishing. p. 652. ISBN 978-0766128170
- Universitetskomiteen, Mediet Einer Nielsen, kontrolundersøkelser av universitetskomiteen i Kristiania. (Kristiania 1922). ”Rapport fra den av Norsk Selskab for Psykisk Forskning nedsatte Kontrolkomité”, Norsk Tidsskrift for Psykisk Forskning 1 (1921-22).
- Chapter The Mechanics of Mediumship in Harry Price. (1939). Fifty Years of Psychical Research. Longmans, Green & Co.
- M. Brady Brower. (2010). Unruly Spirits: The Science of Psychic Phenomena in Modern France. University of Illinois Press. p. 171. ISBN 978-0252077517
- Johs Carstensen. (1932). Spiritismens Princip og Fejlgreb. Specielt: Afsløring af Mediet Einer Nielsen. Brandmose's Forlag.
- Einer Nielsen. (1950). Solid Proofs of Survival. Translated by Helmi Krohn. London: Psychic Book Club.