This study deals with an Catalan evidential marker without a written tradition, but mainly an oral one: diu que (‘(s)he.says.that’, ‘it is said that’), a Romance correlate for dizque (Spanish) or dice che (Italian) (cf. Travis 2006, Cruschina 2015, Alcázar 2018). The spoken, dialectal and, to some extent, residual nature of this marker forces us to search for different sources in order to approach it. The study focuses on the oral recordings of Museu de la Paraula [Word Museum] —an ethnological archive with monological spoken texts— will be completed with the examination of the first results of the colloquial corpus Parlars —a dialectal and informal corpus with monological and dialogical spoken texts. The analysis of diu que and the corpus data show a partially grammaticalized construction with a reportative evidential value. A mirative extension can be also found, but not a pure epistemic meaning. Also, the rise of diu que has been seen as an example of grammatical constructionalization with a tendency towards more subjective meanings, from a quotative strategy to a reportative evidential marker. Related markers such asque diu que or the conventional formula to begin tales això diu que era have been attested.