The 'Surgeon's photograph' (a confessed hoax). Captured by Credited to Robert Kenneth Wilson; staged by Marmaduke Wetherell's circle; April 1934, Loch Ness; published in the Daily Mail. Source: Wikimedia Commons ↗. License: Public domain (PD-old, PD-URAA).
Urquhart Castle on Loch Ness, where Nessie sightings are reported · BIG ALBERT · CC0 (via Wikimedia Commons) · Image source · LicenseCastle Urquhart on Loch Ness, painting by Hugh William Williams; the loch where Nessie sightings are reported · Hugh William Williams · Public domain (via Wikimedia Commons) · Image source
A large, long-necked animal said to live in Loch Ness, Scotland.
DisputedVerdict: Nothing found in decades of searching, and the most famous photo was a hoax.