A former assistant director of intelligence at the FBI said Thursday he finds it hard to believe that former FBI Director James Comey James Brien ComeyDemocrats fear Russia interference could spoil bid to retake Senate Book: FBI sex crimes investigator helped trigger October 2016 public probe of Clinton emails Trump jabs at FBI director over testimony on Russia, antifa MORE was initially unaware of who paid for compiling what's become known as the Steele dossier, a file that contained largely unverified allegations about President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE’s ties to Russia.

“We just had James Comey say in front of Congress last week that he didn’t even know that the [Democratic National Committee] actually funded the dossier that was used to get the surveillance started. Do you find that credible?” Hill.TV’s Buck Sexton asked Kevin Brock, who worked at the FBI for 23 years.

“No, I do not,” said Brock, the founder and principal of public safety firm NewStreet Global Solutions. “I don’t have an opinion on whether he lied or not, but it stretches credulity, in my view, that FBI in possession of this dossier would not have known the source and how it started.”

Brock added that Comey is “throwing the entire rest of the FBI under the bus” by suggesting he was not adequately briefed, adding that this lack of information is “hard to believe.”

Comey last week revealed new details about the Russia investigation during an interview with House lawmakers, including a timeline of when he learned about who financed what's become known as the Steele dossier.

The Washington Post in October first reported in October 2017 that the Hillary Clinton Hillary Diane Rodham ClintonDemocratic groups using Bloomberg money to launch M in Spanish language ads in Florida The Hill's Campaign Report: Presidential polls tighten weeks out from Election Day More than 50 Latino faith leaders endorse Biden MORE Campaign and the Democratic National Committee helped pay for the research that led to the dossier on Trump.

The controversial memo was compiled and authored by former British intelligence officer Christopher Steele, who was hired by U.S. research firm Fusion GPS. His research was funded by the law firm of a lawyer who was representing the Clinton campaign and the DNC at the time. Before that, the research was funded by an unnamed GOP client during the 2016 primary.

Brock argued that Comey, along with former FBI Deputy Director Andrew McCabe Andrew George McCabeGraham: Comey to testify about FBI's Russia probe, Mueller declined invitation Barr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' GOP votes to authorize subpoenas, depositions in Obama-era probe MORE, have subsequently “set the FBI back” and damaged the bureau's reputation.

McCabe stepped down after reportedly facing pressure from FBI Director Christopher Wray, who was said to be concerned about an inspector general report about McCabe and top Department of Justice officials’ actions during the 2016 presidential campaign.

“The FBI has spent over 100 years building a reputation vital to this Democracy of being a strong, independent, objective, arms-length entity from both justice in the White House in pursuing federal criminal investigations," Brock said. "James Comey and Andrew McCabe single handedly set that back a long way.”

—Tess Bonn