George Nader, a Middle East consultant and a prominent witness in the former special counsel Robert Mueller's Russia investigation, has been charged for transporting child pornography, The Washington Post reported.

Nader was also convicted nearly three decades ago of transporting child pornography but got a reduced sentence because US officials argued in court that he was important to an ongoing effort at the time to free American hostages being held in Lebanon.

Nader was a key witness in Mueller's investigation because of his role in several meetings between President Donald Trump's campaign associates and foreign officials suspected of trying to influence White House policy.

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George Nader, a well-known Middle East consultant who was a significant witness in the former special counsel Robert Mueller's Russia investigation, has been charged for transporting child pornography, The Washington Post reported.

According to The Post, Nader, a Lebanese-American businessman, was charged in federal court in Virginia on Monday and is expected to make an initial court appearance in New York.

Nader was convicted nearly three decades ago of transporting child pornography, but he got a reduced sentence after influential officials he was linked to argued in court that he was important to an ongoing effort by the US to free American hostages who were being held in Lebanon at the time.

Nader began cooperating with Mueller's investigation in 2018 after he was subpoenaed upon arriving at Dulles International Airport in Washington, DC.

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Nader provided grand jury testimony about his interactions with President Donald Trump's associates and the role he played in at least two meetings between Trump campaign officials and foreign officials suspected of trying to influence the election and White House policy.

The first known meeting took place at Trump Tower in August 2016 and included Nader, Donald Trump Jr., Blackwater founder Erik Prince, and the Israeli social media specialist Joel Zammel.

The New York Times first reported on the meeting in May 2018, and Prince publicly confirmed its existence this year during an interview with Al Jazeera.

At the meeting, The Times reported that Zammel offered help to Trump's campaign, and Trump Jr. "responded approvingly" to a multimillion-dollar proposal for a social media manipulation campaign to help get his father elected.

In a statement to The Times, Trump Jr.'s lawyer acknowledged a meeting before the 2016 election concerning a "social media platform or marketing strategy," but said his client was "not interested and that was the end of it."

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The second known meeting took place in January 2017 in the Seychelles between Nader, Prince, and the Russian businessman Kirill Dmitriev. Dmitriev is the head of Russia's sovereign wealth fund and an ally of Russian President Vladimir Putin.

The Seychelles meeting invited Mueller's and Congress' scrutiny as investigators examined whether it took place as part of an effort to open a secret back-channel line of communication between the incoming Trump administration and Russia.

Mueller did not ultimately charge Trump or anyone associated with his campaign for conspiring with the Russian government during the 2016 election. Congress is now further investigating Mueller's findings as it weighs whether to impeach Trump or penalize any of his associates.