Even the prosecutor personally selected by Attorney General Bill Barr to review the Russia probe couldn’t find evidence to back up right-wing conspiracy theories about the origins of the investigation.

The Washington Post reported Wednesday that Connecticut US Attorney John Durham, whom Barr tapped in May to examine the origins of the Russia inquiry, said he doesn’t have evidence to back up the allegation that the FBI planted an informant to “spy” on the Trump campaign.

He reportedly told that to Inspector General Michael Horowitz, Justice Department’s independent watchdog, who is carrying out a separate investigation from Durham. Horowitz’s long-awaited report on the Russia probe is expected on Monday.

Reports have suggested the inspector general’s report will criticize the FBI’s handling of some matters relating to the Russia probe, including the alleged falsification of a document by an FBI attorney in the wiretapping of a former Trump aide.

But Horowitz is also expected to broadly say the FBI met the bar to launch the investigation, and that federal law enforcement did not pursue the probe because of political bias against Trump.

The report is also supposed to discredit this idea that the FBI placed informants or spies within the Trump campaign. Trump and his GOP allies have claimed that law enforcement illegally “spied” on the campaign so it could launch an investigation to damage Trump. They argue that this makes the entire Russia investigation illegitimate, or in the president’s parlance, “a hoax.”

The GOP has embraced a theory that a mysterious professor was a plant

The FBI initiated the Russia investigation in July 2016, after receiving disturbing information from an Australian diplomat. The diplomat told them that he’d met with a Trump campaign aide, George Papadopoulos, in London.

During that meeting, which took place in May 2016, the diplomat said that Papadopoulos had drunkenly bragged that he’d been approached by a mysterious professor who claimed to be acting on behalf of the Russian government and would be able to provide the Trump campaign with “dirt” on Hillary Clinton.

But Papadopoulos, who pleaded guilty to lying to the FBI about his contacts with Mifsud as part of special counsel Robert Mueller’s investigation (Mueller took over the Russia probe in 2017), tells a different story. As Vox’s Matthew Yglesias explains, in Papadopoulos’s telling — which has been picked up and amplified by Trump’s right-wing allies — he’s not a liar or a shady campaign staffer trying to get dirt on Clinton. He was set up.

Papadopoulos claims that Mifsud wasn’t connected to Russia at all, but rather was a spy sent by the Italian intelligence service to entrap Papadopoulos as a favor to Obama-era CIA Director John Brennan. In other words, it was all a ruse to set up a Trump campaign aide so that the FBI could launch a fake investigation into the Trump campaign’s ties to Russia.

This theory has taken root, and Horowitz is expected to debunk it. And based on the Post’s reporting, Durham also doesn’t appear to have any evidence to back it up. Durham’s investigation, however, is expected to continue even after Horowitz’s final conclusions are made public next week.

The inspector general report probably won’t settle the debate over the Russia probe

There have been a surprising amount of apparent leaks about Horowitz’s report in recent weeks. Most say the report will find that the FBI was justified in opening up its investigation, but will also spotlight some areas of potential misconduct or sloppiness on the FBI’s part. In other words, there will be something for both Democrats and Republicans to seize on.

Which means the political debate over the Russia investigation probably won’t be settled at all.

Looming above this all is Bill Barr, who has given some credence to the allegation that Trump’s campaign was spied on. The Washington Post reported earlier this week that Barr has taken issue with Horowitz’s finding that the FBI had enough information to open the probe in July 2016.

Barr could submit a letter outlining his concerns to be included in Horowitz’s final report, although whether he or another member of the Justice Department will take this step is not yet clear. But if Durham, Barr’s own handpicked prosecutor, is also unable to find evidence to back up the theory that the FBI entrapped the Trump campaign, it’s sure to raise questions about some of the attorney general’s objections. Specifically, whether they’re substantive or simply political.