Turkey on Sunday dismissed as “ludicrous and groundless” a report that Turkish officials may have discussed kidnapping a U.S.-based Muslim cleric in exchange for millions of dollars.

On Friday, The Wall Street Journal reported that Special Counsel Robert Mueller was investigating an alleged plot involving former U.S. National Security Adviser Michael Flynn and his son to forcibly remove Fethullah Gulen and hand him over to Ankara for as much as $15 million.

Turkey blames Gulen for last year’s failed coup attempt. Gulen denies the claim.

In a statement on Twitter, Turkey’s embassy in Washington reiterated demands that the U.S. extradite Gulen so he can stand trial. The embassy said Turkey has been working with U.S. agencies to provide evidence of Gulen’s culpability and rejected “allegations that Turkey would resort to means external to the rule of law.”

Turkish officials say they have provided U.S. officials with ample evidence for Gulen’s involvement in the coup that killed 250 people. Nearly 50,000 people are behind bars in Turkey and more than 100,000 civil servants have been dismissed from their jobs for alleged links to the cleric’s network.

Yet questions remain whether Gulen would receive a fair trial in Turkey.

The Turkish embassy said the Turkish people find Gulen’s continued refuge in the U.S. “perplexing and deeply frustrating.” Gulen has been living in the U.S. for nearly two decades. He is a former ally of Turkish President Recep Tayyip Erdogan until a public fallout in 2013 led the government to declare Gulen’s network a terror group.