When three defense attorneys representing the alleged terrorist behind the USS Cole attack abruptly quit last October, there were few pieces of concrete evidence to back up their claims of government surveillance. But on Wednesday, new details about a secret microphone found by prison workers became public.

Richard Kammen, Rosa Eliades, and Mary Spears were representing Abd Al-Rahim Hussein Muhammed Abdu Al-Nashir, the alleged mastermind behind the 2000 al-Qaida bombing of the U.S. Navy destroyer that killed 17 soldiers. But they ended their representation, in part, according to a filing obtained by the Miami Herald, after finding a secret microphone hidden in a special client meeting site at Guantanamo Base.

Prosecutors said in the filing that the microphone, which was discovered when prison workers searched the floorboards, inside the walls, and in fixtures, was not turned on and was “not connected to any audio listening/recording device nor in an operable condition.”

Kammen did not immediately respond to VICE News’ request for comment, but he told the Miami Herald this week that although it was “good” to see evidence coming out, “the reality is more than what they’ve declassified.”

Kammen, who quit the case on Oct. 13 along with the two other lawyers, argued in November that his representation of Nashiri had been "irreparably ethically compromised" by what he alleged to be government surveillance.

After the judge ordered him to continue representing Nashiri, Kammen wrote that he faced a “Solomonic choice.” Either he would be “compelled to provide unethical, ineffective legal services,” which would put his bar license at risk,” litigate death penalty case by video, which would violate Indiana’s code of conduct for lawyers, or remove himself from the case and risk being “forcibly apprehended and punished by Colonel Spath."

Kammen was saved from being compelled to appear after a U.S. district judge ruled he shouldn’t be held in custody while the case played out, the Indy Star reported. However, Spath did order the military commission to subpoena and draft warrants for Kammen’s co-counsels, insisting that “no intrusions occurred in any meeting between Mr. al Nashiri and his attorneys.”

In February, a frustrated Judge Spath decided to halt the proceedings indefinitely. He didn’t dismiss the case entirely, adding, “the reason I'm not dismissing -- I debated it for hours -- I am not rewarding the defense for their clear misbehavior and misconduct. That would be the wrong answer. But I am abating these procedures -- these proceedings indefinitely until a superior court orders me to resume.”

Since then, it’s been legal ping-pong. Military prosecutors appealed the judge’s decision to halt the case on Feb 21. A week later, the lone attorney now representing Nashiri, Navy Navy Lt. Alaric Piette, submitted a filing appealing the military prosecutors’ appeal.