The tiles at Sixth and Olive streets, which together read "Toynbee Idea In Kubrick's 2001 Resurrect Dead On Planet Jupiter," were first placed 25 years ago and the final two tiles were taken by a man during the summer, the St. Louis Post-Dispatch reported Wednesday.
Similar tiles have been found in Philadelphia, New York, Boston, Washington, Baltimore, Cleveland and cities in Brazil, Argentina and Chile.
The mysterious origins of the tiles were the subject of a documentary film last year titled "Resurrect Dead: The Mystery of the Toynbee Tiles."
Kelley Huonker, 30, of St. Louis, said she went in search of the tiles in August and was told by a security guard that they had been removed by a man two weeks earlier.
"(The guard) said he asked the guy what he was doing, and the guy said that a documentary had been made about these things and they're going to be worth a lot of money someday," Huonker said.
The tiles are thought to be a reference to English historian Arnold Toynbee, whose theory on regenerating dead molecules appeared in Stanley Kubrick's movie "2001: A Space Odyssey."