The convenience was built for a visit on Monday by Princess Maha Chakri Sirindhorn to Yeak Lom lake in northeastern Cambodia.
But her two-hour visit ended without her ever having experienced the lavish water closet, community leader Ven Churk told AFP.
The toilet was later "removed" and the adjoining bathroom will now be turned into a security post for tourists visiting the tree-ringed lake, he added.
The toilet took more than two weeks to build and cost an estimated USD 40,000, Ven Churk told AFP.
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"I have never seen such a bathroom," he said.
Provincial governor Nhem Sam Oeun confirmed the toilet was unused, adding the loo is "very modern, very good... It can't be kept because it is for royals."
The Thai side covered the construction costs, he added.
Local media reports said the luxury pan was built by the Siam Cement Group, a Thai construction giant partly owned by the Crown Property Bureau, which manages the Thai royal family's assets and investments.
While the pricey privy has made international headlines it has not received any media attention in Thailand, where a severe lese majeste law punishes any perceived criticism of the royal family with up to 15 years prison.
Tin Luong, the chief of Yeak Lom commune, told AFP he was impressed by the "very beautiful" bathroom.
"Thai engineers have constructed the bathroom," he said confirming all of the materials were brought from Thailand.
"I estimate that it could cost up to USD 40,000 to build the bathroom. It looks like a house with beautiful decoration," he added.
Thailand's monarchy is among the world's richest, with its fortune in part built through investments in major local businesses such as SCG and Siam Commercial Bank.
After visiting the lake, the princess opened a new health centre that was donated by the Thai royal family. She also met with Cambodia's Prime Minister Hun Sen during the visit.