The burials of at least two priests of Amun from a later period than the construction of the tomb have been found. Their names are Wedjahor and Horempe (also written Horenpe); you can see some of their coffin fragments on the Coffins page. It happens that we found a fragment of mummy bandage with the name and some titles of Wedjahor, on which was a year 10, and in more or less the same place, a fragment with the titulary of king Shabaka, who was the first king of the 25th dynasty to rule over a fully united Egypt, and reigned between about 715 and 700 BC. Up to now the date of Wedjahor has been uncertain (Kitchen in The Third Intermediate Period in Egypt suggested the 7th century BC, and Vittmann in Priester und Beamte von Theben der Spätzeit the 8th century BC), and we think we can bring the two fragments together, since on one mummy a fragment of linen of the same type bearing part of the titulary of Shabaka was found. Thus this mummy is in all probability that of Wedjahor and we can suggest that we was probably buried in about 705 BC.
As for Horempe, we have a piece of linen with a year 12 on it, but no way to date it further from the tomb. However, there is a statue of Horempe in the Cairo Museum (JE 36970), originally from the famous cachette in Karnak, which names him as the son of Wedjahor. I assume that it is more probable that he did not die two years after his father, and the next king with a reign long enough to accommodate a year 12 is Taharqa, who reigned from about 690 to 664 BC. So I would suggest that Horempe died in about 678 BC. The next king with the right sort of reign length is Psammetichos I, and that would mean Horempe's burial taking place in 652 BC, which seems probably too late.
It so happens that Wedjahor also has a statue in the Cairo Museum (JE 37153), and I have been granted permission by Dr Mohamed Saleh, Director of the Museum, to publish both statues. So while you all await the final publication (but please don't hold your breath), here are photographs of the statues:
I hope that you will agree that these are both very fine pieces of Egyptian sculpture. They belong to the so-called 'block statue' type, for obvious reasons. What I find most fascinating about them is their similarity of features, which tends to suggest that they were made in the same workshop. It would be interesting to know if they were made at the same time too. They are among the earliest datable block statues of the 25th-26th dynasty period. See B.V. Bothmer, in Hommages à Jean Leclant II, 61-8.
Both statues now feature in the highly recommended 'Karnak Cachette' Database of the IFAO and SCA. Clicking on the two pictures above will take you directly to the database entries for the statues.
TT99 thus contains the remains of one of the best datable tomb groups of this period, as most of them can only be dated by relative means, e.g. family genealogies, and not absolute dates.