When Fusion GPS founder Glenn Simpson appears before the House Intelligence Committee on Tuesday, he will face a litany of questions about the dossier that his firm commissioned last year on behalf of the Clinton campaign and Democratic National Committee.

Here are some under-the-radar questions that Simpson, a former Wall Street Journal reporter, could be asked.

Was Glenn Simpson told at all about the Trump Tower meeting?

Simpson worked alongside a key figure in the June 9, 2016 Trump Tower meeting — Russian attorney Natalia Veselnitskaya. The pair were working on a case aimed at undercutting the Magnitsky Act, a sanctions law that blacklists Russians accused of human rights abuses.

Fusion GPS has denied in statements that Simpson or Fusion knew anything about the Trump Tower meeting. But that claim came under scrutiny last week when Fox News reported that Simpson met with Veselnitskaya before and after she visited Trump Tower.

Veselnitskaya took a four-page memo into that meeting which used research compiled by Simpson and Fusion.

House investigators will likely want to know whether Simpson knew of the meeting in advance, or whether Veselnitskaya made any reference to it.

They are also likely to question whether Simpson shared anything he heard from Veselnitskaya with Christopher Steele, the former British spy who wrote the 35-page dossier.

Were the Clinton campaign and DNC involved in Fusion GPS’s media outreach campaign?

Steele has revealed in a court in London, where he is being sued over the dossier, that he was directed by Fusion GPS to brief reporters in late Summer 2016 about his investigation into Donald Trump’s activities in Russia.

Steele briefed reporters from The New York Times, The Washington Post, CNN, Mother Jones, The New Yorker and Yahoo! News as part of the media outreach campaign. A reporter at the BBC has also written that Simpson showed him the dossier just before the election. (RELATED: Details Emerge About Fusion GPS’s Media Outreach Campaign)

And Carter Page, a former Trump campaign adviser, has testified that he was contacted by a Wall Street Journal reporter on July 26, 2016 about claims that originated in the dossier.

The media outreach effort undercuts Democrats’ claims that Steele’s uncorroborated findings were not disseminated to the press or to the public. Yahoo! News and Mother Jones published articles prior to the election based on some of Steele’s unverified allegations.

It is still unclear whether Fusion GPS and Simpson decided to brief reporters on their own or if the Clinton campaign and DNC gave instructions to do so.

Does Simpson know who gave the dossier to BuzzFeed?

Fusion has denied in court filings that it provided the dossier to BuzzFeed News, which published the salacious document on Jan. 10. Fusion has acknowledged that the website asked for a copy of the report.

Simpson and Fusion are likely to know who all had access to the full version of the dossier and would be in a position to shed light on the identity of BuzzFeed’s source. (RELATED: New Court Filings Re-Open Question Of Who Gave Dossier To BuzzFeed)

Did Simpson know that his research was being provided to a top Kremlin official?

It was revealed last week that information that Veselnitskaya, the Russian lawyer, gave to Donald Trump Jr. in the Trump Tower meeting as well as to Russia’s prosecutor general, Yuri Chaika, was compiled by Simpson and Fusion GPS.

The memos made a series of allegations about Bill Browder, a London-based banker who is responsible for pushing through the Magnitsky Act, which the Kremlin vehemently opposes. (RELATED: Anti-Kremlin Banker Accuses Fusion GPS Of Helping Putin Regime)

Whether Simpson knew that his work product was being shared with the Kremlin or with Trump Jr. remains an unanswered question. Browder has accused Simpson of violating the Foreign Agents Registration Act for failing to register as a foreign agent of Russia.

Was Simpson aware that Steele briefed the FBI about the dossier?

Steele first met with FBI agents in early July 2016, several weeks before the bureau opened its investigation of the Trump campaign. What remains unknown is whether Simpson knew that Steele was sharing his allegations with the FBI.

Steele briefed reporters after being directed to do so by Fusion, so it’s possible that he spoke with the FBI based on similar instructions.

Fusion’s involvement in sparking an investigation of Trump would be of interest to Republicans, especially since the oppo firm was working at the time for Democrats.

The existence of a federal investigation was used as a news hook for articles that included allegations made about the Trump campaign in the dossier.

Such was the case with a Sept. 23, 2016 article by Yahoo! News’ Michael Isikoff. Isikoff, who was briefed by Steele, reported some of the allegations that the ex-spook made about former Trump campaign adviser Carter Page in the dossier. The article uses the existence of a federal investigation as justification for reporting the unverified allegations about Page, such as that he met in secret with top Kremlin officials and that he was the Trump campaign’s chief colluder.

Notably, the first person to tweet Isikoff’s piece was Jesse Lehrich, a Clinton campaign adviser.

Page has vehemently denied the allegations made in the dossier. He is suing Yahoo’s parent company.

Did Glenn Simpson and Clinton campaign chairman John Podesta discuss who paid for the dossier?

Though the Clinton campaign and DNC are now known to have paid Fusion GPS for the dossier project, John Podesta told the Senate Intelligence Committee in a previous interview that he did not know who funded the Trump investigation.

Podesta was in the Senate interview with his lawyer, Marc Elias. Elias was general counsel to the campaign and DNC and made the arrangements with Fusion GPS to conduct the Trump probe. The attorney did not acknowledge his involvement with Fusion GPS. (RELATED: John Podesta Met With Glenn Simpson After Dossier Was Published)

The New York Times reported on Friday that Podesta and Simpson met just after the dossier was published in order to exchange notes on Trump and Russia. The Times report did not address whether Podesta acknowledged that the campaign is who paid Fusion. Though if the matter was discussed, Podesta could find himself on the bad side of a perjury charge.

Did Fusion continue the research and investigation into Trump after the dossier was published?

According to the Times, Simpson and Podesta discussed whether to continue probing Trump’s alleged ties to Russia. It is not known whether Fusion GPS continued doing so after the dossier was published.

What was Fusion’s arrangement with journalists?

The House Intelligence Committee, which has issued a subpoena for Fusion GPS’s bank records, recently asked the firm for information on financial transactions “with any law firm, ‘media company’ or journalist with which it has worked.”

Fusion’s response has stoked speculation that it has paid journalists.

“None of those demands are pertinent to the Committee’s ‘Russia investigation,’ and disclosure of the documents would cause irreparable harm to Plaintiff by destroying the confidentiality of its business with its clients and contractors and by violating Plaintiff’s First Amendment rights to free speech and free association,” Fusion GPS’s lawyers wrote in response to the House panel. (RELATED: House Intel Committee And Fusion GPS Renew Battle Over Bank Records)

Fusion has contracted with several former journalists from outlets like The Wall Street Journal, Los Angeles Times, and Dayton Daily News, but it is unclear whether there have been any transactions with current reporters.

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