FBI agents infiltrated an alleged plot to kidnap and hurt Gov. Gretchen Whitmer by hiding recording devices in key fobs that captured conversations among undercover informants and accused plotters, according to a court filing late Monday.

A defense lawyer for one of the accused ringleaders, Potterville resident Adam Fox, 38, argued conversations captured by the spy gadget will prove there was no conspiracy to kidnap Whitmer and that the government entrapped five men awaiting trial in a case that has focused attention on “violent extremism” in Michigan. Defense lawyers are fighting to play the recordings for jurors during a trial starting in March in federal court in Grand Rapids.

“Adam Fox asserts that portions of these same recordings and messages show that there was no agreement between the defendants to commit a crime and that the government through its informants and agents entrapped the defendants into the limited participation the government did induce,” Fox lawyer Christopher Gibbons wrote Monday.