Wasn't a perfectly persevered bust of Octavian found in the sands of Nubia? It may well have been stolen by the Nubians during Cornelius Gallus' term as prefect of Egypt (26-23 BC); during which he, as stated above, led an unsuccessful raid into Nubia (the result of which is greatly falsified when referred to in Augustus' Res Gestae), and was on the receiving end of a counter attack led by the Nubian queen, Candace Amanirenas. Both of these disastrous events brought Gallus into disgrace, and rather than face prosecution by Augustus, he took his own life.
However, the bust could just as well be evidence for Roman influence spreading to this area outside the imperial wing of the empire. Though having said this, the former explanation seems to be more likely.
Anyway, if my memory serves me correctly, I do believe the bust is on display in the British Museum.