Former intelligence officer Christopher Steele has warned about the danger of discussing sources.
It comes after a US investigation published details about people who it said contributed to a dossier that he compiled on alleged Russian links to Donald Trump’s election campaign.
The long-serving veteran of Britain’s Secret Intelligence Service (MI6) also hit back at the findings of the investigation by the US Department of Justice’s inspector general, which were released on Monday.
The top complaint was on claims in the report about a “primary sub-source” that was allegedly relied upon by Mr Steele in his compilation of the so-called Trump dossier.
Inspector General Michael Horowitz – who was looking into the origins of an inquiry by the Federal Bureau of Investigation (FBI) into the Russia suspicions – set out how the FBI had interviewed who they believed to be Mr Steele’s “primary sub-source” in January, March and May 2017.
His report claimed these interviews “raised significant questions about the reliability of the Steele election reporting”.
It continued: “During the FBI’s January interview, the primary sub-source told the FBI that he/she had not seen Steele’s reports until they became public that month, and that he/she made statements indicating that Steele misstated or exaggerated the Primary Sub-source’s statements in multiple sections of the reporting.”
Mr Steele and Orbis Business Intelligence – his private intelligence company – said in a statement that they were never given the opportunity to respond to these claims.
“Public discussions about a source are always fraught with danger for the source and the source’s sub-sources,” said the statement, released by their lawyers.
“Had Orbis been given the opportunity to respond in a private session, the statements by the ‘primary sub-source’ would be put in a very different light. The ‘primary sub-source’s’ debriefings by Orbis were meticulously documented and recorded”.
The former intelligence officer and his company also described how they had cooperated “voluntarily and fully” with Mr Horowitz’s during his inquiry.
“Orbis also provided the OIG (Office of the Inspector General) team unprecedented access to Orbis internal company documentation, including contemporaneous memoranda of meetings with the FBI,” they said in the statement.
They added that Mr Horowitz’s team did give Orbis redacted portions of a draft version of the report to review and offer comment on in advance of publication.
“Those portions contained numerous inaccurate and misleading statements as to which Orbis submitted suggested corrections and clarifications,” said the statement.
“Some of Orbis’s suggestions appear to be reflected in the final report.”
Mr Steele and his company then said that “at the twelfth hour late on Sunday evening” – they were told that previously redacted material had been unredacted and contained negative material about Mr Steele.
“Orbis was given no opportunity to review, much less comment, on this material,” they said.
“The result is that the OIG Report contains several serious errors and misstatements that require this response.”
In other criticisms of the report, Mr Steele and Orbis also denied a claim that he had been a Confidential Human Source (CHS) to the FBI during a relationship that started in 2010 and became a more formal contractual relationship between 2013 and 2016.
During that time Mr Steele, a Russia expert, provided information that helped the FBI in other Russia-linked investigations, including work on FIFA and athletics doping.
The Justice Department did not immediately respond to a request for comment.