(Reuters) - Parler, a social media app popular among right-wing users, is being sued by co-founder John Matze for wrongful termination and taking away his 40% stake after the app was taken offline following the Jan. 6 riot at the U.S. Capitol.In a complaint filed on Monday, Matze said Parler officials and investors conspired to steal his ownership stake and fire him as chief executive, including by leveling false accusations of misconduct, so co-owner Rebekah Mercer could co-opt the platform for “her brand of conservatism.” He said this occurred after Parler resisted his efforts following the riot to ban “identifiable extremist groups like QAnon and neo Nazis,” while preserving the platform as a forum for free expression. “Matze’s proposal was met with dead silence, which he took to be a rejection of his proposal,” the complaint said. Lawyers for the Parler defendants did not immediately respond to requests for comment or could not immediately be reached. Mercer’s father is the wealthy financier and Republican donor Robert Mercer. Matze is seeking millions of dollars in his lawsuit filed in a Nevada state court in Clark County, which includes Las Vegas. Parler is based in nearby Henderson, Nevada. The lawsuit did not say what Matze’s Parler stake was worth, but accused various defendants of fabricating misconduct claims to justify stripping it from him for $3. Parler went dark for about one month after Amazon.com Inc suspended web-hosting services following the Capitol attack by supporters of then-U.S. President Donald Trump. Amazon justified its action by accusing Parler of failing to effectively moderate violent content. Parler later sued Amazon, accusing it of trying to destroy its business. Apple Inc and Alphabet Inc’s Google also removed Parler from their online stores. Founded in 2018, Parler claimed to have had more than 12 million users before going dark. It returned online with private cloud infrastructure from SkySilk, of Los Angeles. Matze’s complaint was posted online by the Las Vegas Sun. A copy could not immediately be located in online court records.