Skinny dippers visiting Loch Lee in Cairngorms National Park were emerging from the water to find their garments had gone awol.
The naked truth was only revealed when bird watchers spotted the theives in action.
It turns out that red kites were pinching the knickers and socks to line their nests.
"It was like the kites were cleaning up the glen," said local gamekeeper Dave Clement.
Nudists are now being advised to hide their clothes before heading in for a bare-fleshed frolic.
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