A British author who specializes in espionage raised serious doubts about former MI6 officer Christopher Steele's salacious dossier, which was included in the FBI's counterintelligence investigation into President Trump's 2016 campaign.

Rupert Allason, a former member of Parliament whose pen name is Nigel West, conducted a forensic analysis of Steele's work, which made stunning allegations about coordination between Trump's camp and Russia. He came away "stunned" by what he viewed to be a poor job by a former intelligence officer whom he once considered to be a friend.

“There is ... a strong possibility that all Steele’s material has been fabricated," Allason wrote in a report obtained by the British newspaper Sunday Times.

Allason, 68, was commissioned by a Republican law firm after the dossier, a series of reports that included details of an alleged video obtained by the Russians of Trump with prostitutes urinating on a bed in a Moscow hotel room, was published by BuzzFeed in January 2017.

Allason's report comes in the wake of an assessment by Justice Department Inspector General Michael Horowitz, who condemned Steele, 55, and the FBI for its reliance on his dossier to obtain warrants for wiretapping onetime Trump campaign adviser Carter Page. Additionally, special counsel Robert Mueller concluded an investigation last year that found no criminal conspiracy between the Trump campaign and Russia.

The FBI has been heavily criticized by Trump and his Republican allies for not making clear to the Foreign Intelligence Surveillance Court that Steele's work, commissioned by the opposition research firm Fusion GPS, was funded by Hillary Clinton's 2016 campaign and the Democratic National Committee through the Perkins Coie law firm.

Allason determined that because Steele had Democratic benefactors, he had "a strong financial incentive to perpetuate the reporting" of Trump's links to Russia.

Horowitz's report, which was released in December and faulted the Justice Department and the FBI for 17 “significant errors and omissions” in its submissions to the FISA court, showed that FBI interviews with Steele's primary Moscow-based source, beginning in January 2017, "raised significant questions about the reliability of the Steele election reporting." This source claimed that much of what he told Steele was "hearsay" or, in the case of the "pee tape," just "rumor and speculation" from a sub-source, reported by some to likely be Belarus-born businessman Sergei Millian. Millian, however, has denied being a source for the dossier.

Allason also took issue with Steele's sourcing, writing that from "a professional intelligence perspective, the dossier as a whole is profoundly troubling and cannot be taken at face value."

“Source E is credited with access to Ritz-Carlton staff, knowledge of Russian government involvement with WikiLeaks and the abuse of Russian diplomatic facilities in the United States. This appears to be an extraordinarily wide area of expertise," Allason wrote, adding, "The apparent lapses bear the hallmarks of invention."

In a statement, Steele's Orbis Business Intelligence accused Allason of writing a "politically motivated" report as his research was funded by a Republican law firm and asserted that Allason's findings were not "based on any knowledge" of its sources and methods.

West's work, the firm said, "lacks authority" because he "was never an intelligence officer and has no experience of operational work in the field." Orbis also claimed "much of the dossier has been proven” since 2017 and declared: “We stand by the integrity and quality of our work.”