Reeves said the team first discovered what he believes is a tomb back in 2000 when taking electronic surveys of the area using high-tech radar equipment.
At the time, they noticed two "anomalies," one which turned out to be KV-63 and another which has the same characteristics as KV-63, but which has yet to be uncovered.
Though there are no plans to begin digging as of yet, Reeves hopes that alerting the public to the possible existence of another tomb will ease pressure on Egyptologists working in the area to speed up their laborious work.
On the Web site for the Valley of the Kings Foundation, of which Reeves is a member, he wrote:
"Faced with evidence for a second intact tomb in the Valley of the Kings, those who understand the nature of the archaeological game in Egypt will feel not excitement but an overwhelming anxiety, for there will be inevitable pressure for quick results. This pressure must be resisted: Speed equates to loss, and it falls to the responsibility of every one of us to ensure that Egypt and Egyptology are not denied the further, extraordinary opportunity they are now presented with.
"KV-64 must be the platform from which to insist that any and all future investigations in the Valley of the Kings are approached with immense caution and carried out methodically to a larger plan by well-funded, professional archaeologists sensitive to all the site's possibilities and needs. The recovery of every ounce of the Valley's remaining potential must be the aim -- nothing less will do.
"If Egyptology cannot meet these basic obligations, then clearly, no further work should be contemplated; all archaeology is destruction, and it stands to reason that what has been dug foolishly and in haste cannot later be undug sensibly and at leisure. Let us try, this time around, to get it right."