The area of Bidau, in the East Timorese capital of Dili, was home to the only documented form of Creole Portuguese in Timor. Although Bidau Creole Portuguese is now extinct, by most accounts, a few scattered records allow a glimpse into what it must have been like, and reveal its clear relationship with other Southeast Asian Portuguese-based creoles; study of Bidau Creole Portuguese was based mostly on a set of recordings made in the context of the Missão Antropológica de Timor [“Anthropological Mission to Timor”, 1953–1954]. In this article, mentions that “[s]o far, the earliest located reference to Bidau Creole Portuguese, and one which contains some impressionistic examples of conversations and the verse of a song, is ”. However, since the publication of this study, a few earlier references to what can be interpreted as Portuguese-based creole in Timor have been located in unpublished archival sources. These sources are letters sent to two important philologists of the late 19th and early 20th century, Hugo Schuchardt and José Leite de Vasconcelos, who were greatly interested in ascertaining whether a creole was spoken in Timor and what the local Portuguese was like. The present study introduces and contextualises these epistolary sources, discussing the linguistic and sociolinguistic material contained therein, and its relevance for the confirmation of different threads of language contact involving Portuguese.