=== Alleged Jewish heritage ===
Rumors appearing on various Catholic or [[Sedevacantism|sedevacantist]] websitesref and magazinesref alleged that Malachi Martin had [[Jew]]ish ancestry on account of ancestral descent from [[Iberia]]n Jews migrating to Ireland and Great Britain in the 15th century, and alleged him being an [[Israel]]i spyref because of his first name, [[Malachi]], after a Hebrew prophet and his extensive travels in the [[Levant]]. These allegations were rebutted by William H. Kennedy in his article In Defense of Father Malachi Martin.ref After having made genealogical inquiries with surviving relatives of Martin in Ireland, Kennedy concluded that Martin's father was an Englishman who moved to Ireland and his mother was fully Irish. Fr. [[Rama Coomasrawamy]] confirmed this independently.ref The [[Irish language]] name Maelsechlainn is usually anglicised as .
=== Alleged photograph ===
Claims that Martin features as a curial [[monsignor]] in full [[regalia]] on a prominent photograph next to Pope John Paul I and his assistant [[Diego Lorenzi]] appeared on the Internet.ref The photograph, published in [[David Yallop]]'s In God's Name: An Investigation into the Murder of Pope John Paul I as number 28 between pages 120 and 121, shows a 'Monsignor Martin', visibly different from Malachi Martin.ref This is a case of [[mistaken identity]]: the cleric in the photograph was [[Jacques-Paul Martin]], [[...| Prefect of the Casa Pontificia]] between 1969–86.refref