This Rattus is known from very few specimens collected in the Arfak Mountains of Indonesian New Guinea. The 2005 taxonomic account treated it provisionally as distinct because its relationship to the R. niobe group was unresolved.
The 2005 taxonomic account describes the upperparts as dark brown. Few specimens are available, so variation in appearance is not well documented.
A 2016 global review assigns rainforest as the habitat category for this type-locality species. Its table lists Papua New Guinea, however, while the current MDD places the Arfak type locality in Indonesia. This is a broad assessment category, not a direct field observation.
An extinction-risk assessment has not been added yet.