Nick Pope, former UFO investigator for the UK Ministry of Defence, has urged the Pentagon to release a photo that allegedly shows a 100ft diamond-shaped object spotted hovering over Calvine in the Scottish Highlands back in 1990, The Sun reports.
According to the newspaper, the photo in question was described by Pope as one of the "most compelling" pieces of "UFO evidence" he ever encountered.
According to the newspaper, while the picture once used to adorn the wall of the UFO investigations unit in Whitehall, it ended up being "removed without a trace" and kept "under wraps" following a diplomatic row that ensued when the MoD “questioned the Americans about whether they were testing any secret prototype aircraft in the area."
"I hope we get the Calvine photo back, I hope we find the US government had a copy – I am sure they do – and I hope they publish it in the report as the MoD say it’s either lost or under lock and key for another few decades," Pope said.
The missing picture is reportedly believed to be a part of a whole series of images taken during the same alleged UFO incident.
"The photos are pretty much as good as it gets. They were assessed by defence intelligence staff as real - they were clearly visible, sharp focused, broad daylight with the Scottish countryside in the background," Pope remarked.
The UFO investigator’s revelations come ahead of the upcoming Pentagon report on Unidentified Aerial Phenomena (UAP).