Based on visual sightings and camera-trap photographs, an unusual form of giant sengi or elephant-shrew in the genus Rhynchocyon is identified from the Udzungwa Mountains of south-central Tanzania, which are already known for their extremely high biodiversity and endemism. This unique sengi appears to occur only in the Ndundulu, Mount Luhomero, and, possibly, Mwanihana forests and may therefore be of considerable conservation concern. A full description of this taxon, including formal naming, must await the collection and analysis of voucher specimens, which probably will take many months. In the meantime, it is important that conservationists focussing on the Eastern Arc Mountains be aware of the occurrence of this potentially new Rhynchocyon and field biologists participate in gathering additional information, especially on its distribution.