Former FBI official Peter Strzok told Special Counsel Robert Mueller early in the Trump-Russia probe that he doubted the Trump campaign conspired with the Russian government to influence the 2016 election, saying that the president’s associates were “a confederacy of dunces who were too dumb to collude” with the Kremlin.

Strzok shared details of his interaction with Mueller in his book, “Compromised,” which hits stores on Tuesday.

“Is this a coordinated conspiracy?” Mueller asked Strzok, according to the book, details of which were reported by NBC News.

“I was skeptical that all the different threads amounted to anything more than bumbling incompetence, a confederacy of dunces who were too dumb to collude,” wrote Strzok, who served as deputy chief of FBI counterintelligence during the Trump probe.

“In my view they were most likely a collection of grifters pursuing individual personal interests.”

Strzok’s remarks provide rare insight into what FBI investigators thought about the prospect of Trump-Russia collusion early in the investigation.

Strzok served on the special counsel’s team for only a couple of months, through late July 2017. Mueller removed him from the investigation after the discovery of anti-Trump text messages he exchanged with then-FBI lawyer Lisa Page.

Though Strzok doubted that collusion occurred between the Trump team and Russia, Mueller continued his investigation through March 2019.

Strzok opened Crossfire Hurricane on July 31, 2016 after the FBI received information from the Australian government regarding an interaction two months earlier between Trump campaign adviser George Papadopoulos and Australian diplomat Alexander Downer.

Downer said that Papadopoulos told him in a conversation on May 10, 2016 that Russia may release information later in the campaign that would help Trump’s election effort.

The FBI investigated whether Papadopoulos or any other Trump associate helped the Russian government steal or release emails hacked from the DNC and Clinton campaign.

A report from the special counsel’s office said that investigators were unable to establish that any Trump associates conspired with Russia or acted as agents of the Russian government.

Strzok indicated in a text message to Lisa Page on May 18, 2017, the day after Mueller took over as special counsel, that he did not believe that the investigation would find a vast Trump-Russia conspiracy.

Strzok told Page that he was hesitant to join Mueller’s team because he doubted that Trump associates had conspired with the Russian government.

“You and I both know the odds are nothing. If I thought it was likely I’d be there no question. I hesitate in part because of my gut sense and concern there’s no big there there,” he wrote.

While Strzok writes that he does not believe that Trump or his associates conspired directly with Russia, he does think that the president is compromised by Vladimir Putin. Strzok asserts in the book that Trump’s attempts to do business in Russia, and his denials of having any links to the country have made him vulnerable to manipulation from Putin.

“Putin knew he had lied. And Trump knew that Putin knew — a shared understanding that provided the framework for a potentially coercive relationship between the president of the United States and the leader of one of our greatest adversaries,” Strzok writes, according to NBC News.