In March 2016, the FBI arrested Iran-based Reza Zarrab in Miami, Florida. Zarrab was accused of bank fraud and money laundering to help Turkish President Recep Erdogan and other members of the Turkish government evade US sanctions against Iran. Zarrab is currently in federal prison in Manhattan.
Turkey’s president Erdogan has made several attempts to obtain Zarrab’s release, including personally asking Vice President Joe Biden to drop the case and to fire the US Attorney leading his prosecution, Preet Bharara. Source Donald Trump eventually did fire Bharara in 2017 – see Prevezon Holdings.
In late December 2016, Michael Flynn allegedly met with several senior Turkish officials to discuss the deportation of Fethullah Gulen to Turkey. During this meeting, the parties also allegedly discussed how to arrange for the release of Reza Zarrab. In exchange for Gulen’s deportation and Zarrab’s release, it is alleged that Michael Flynn would receive more than $15 million from Turkish president Erdogan. Flynn’s son, Michael G. Flynn, is also being investigated in relation to this alleged meeting. Source
In early 2017, former New York mayor and Donald Trump ally Rudy Giuliani, and former US attorney general Michael Mukasey joined Zarrab’s defense team. In late February 2017, Giuliani and Mukasey visited Turkey to meet President Erdogan to try to negotiate a deal to secure Zarrab’s release. The available reports indicate that the negotiations did not involve the US Attorney’s office for the Southern District of New York, which is prosecuting Zarrab. Rather, the Giuliani/Mukasey team apparently negotiated on behalf of the United States, offering Zarrab’s release in exchange for “Turkey’s help furthering US interests.” Source