The 36-year-old singer -- who collects watches -- claims in his lawsuit that he met watch dealer Robert Maron in 2007 and told him he was looking for a rare Rolex for his collection. At the time, Maron sold Mayer a number of watches which seemed to be original, but in 2010, when the "Gravity" singer sent one of the timepieces to the manufacturer for repair, he was told that "the watch was not authentic in all respects."
Mayer then confronted Maron, who admitted that Rolex was right and gave the singer a refund for the "isolated event" of having sold him a fake watch.
Later in 2011, Mayer learned that seven of the watches he bought from Maron were fake. The singer claims he paid $656,000 for the counterfeit pieces and that other watches he purchased from Maron were originals.
Maron's lawyer told TMZ that Mayer's lawsuit was "legally and factually merit-less."
"John Mayer, who briefly claimed expertise in Rolexes but now has apparently changed his mind, has brought a lawsuit that is legally and factually meritless," attorney Eric George said. "Mr. Maron refuses to pay Mr. Mayer a cent to settle his frivolous claim, and will instead defeat him in court."
Maron and Sheen know each other because the latter also collects watches. The two eventually became close friends and Maron even became the actor's manager at one point.