A key witness in the investigation into President Donald Trump's alleged collusion with Russia has fled the country, DailyMail.com can disclose.

Convicted pedophile George Nader was allegedly both a paid adviser for the United Arab Emirates and had close ties to the Trump administration.

He met Jared Kushner and Steve Bannon in Trump Tower just before the inauguration at a meeting they held with the de facto ruler of the United Arab Emirates.

Nader was thrust into the limelight after being interviewed twice by special counsel Robert Mueller as part of his probe into Russian meddling in the US election and collusion with the Trump campaign team.

Now DailyMail.com can reveal he has flown back to the UAE, according to two sources close to the country's de-facto ruler Mohammed bin Zayed, who is known by his initials 'MBZ.

The revelation comes just days after Nader was revealed to be a convicted pedophile.

George Nader (left), who was allegedly both a paid adviser for the United Arab Emirates and had close ties to the Trump administration, has flown back to the UAE. Sources close to the country's de-facto ruler Mohammed bin Zayed (right), known by his initials 'MBZ', revealed that Nader had fled the United States

Meeting: Steve Bannon and Jared Kushner's Trump Tower meeting with MBZ in December 2016 has been a focus for Robert Mueller - and George Nader who was present and may have helped broker it had been co-operating with the special counsel probe

The Lebanese-born adviser was first stopped when he flew into Washington in January on his way to visit Trump's Mar-a-Lago resort and served with a subpoena.

Investigators seized his phone and he was hauled in front of Mueller's team, with whom - his lawyer has said - he has been cooperating.

Mueller is focusing on two meetings. The first is a December 2016 meeting Nader is believed to have organized at Trump Tower involving Kushner, Bannon met MBZ.

The meeting raised concerns in the Obama administration because the plan for MBZ to meet the Trump transition was never disclosed to the White House or State Department in a breach of protocol for meetings with foreign leader.

They only became aware of it when his name was spotted on a passenger manifest.

Investigators are also interested in a January 2017 meeting he was present at and may have helped organize in the Seychelles, attended by billionaire Blackwater founder Erik Prince - whose sister is education secretary Betsy DeVos - and Zayed.

During the visit, Prince also met with Kirill Dmitriev, a Russian oligarch who is close to Russian President Vladimir Putin.

Mueller is investigating whether Nader helped steer money to help Trump politically, the New York Times reported earlier this month.

But a source close to Zayed has said that Nader has now fled to the UAE after the Emirati prince pulled strings with US officials to secure his freedom to move.

'George Nader left the US. Where is he now? He fled,' said the source.

'He can run but he can't hide. There's a subpoena. His whole file is in Mueller's hands now, everything.'

Nader was thrust into the limelight after being interviewed twice by special counsel Robert Mueller (pictured) as part of his probe into Russian meddling in the US election and collusion with the Trump campaign team

A second source close to the Emirati royal family said Zayed is keen to know what Mueller asked his top adviser.

'George is back in the UAE, though I thought he'd be too scared to go there,' said the source. 'The fact that he's gone back there means he's obviously not worried. But MBZ is going to want to see him and know what he told the special counsel.'

Nader is understood to have helped broker a meeting in the Seychelles last year just days before Trump's inauguration, between infamous mercenary firm Blackwater founder Erik Prince, Russian banker and friend of Putin Kirill Dmitriev, and two top UAE officials.

Prince claims the meeting was set up in the Seychelles to discuss counter-terrorism efforts with the Emiratis – despite the security contractor already living in Abu Dhabi near to Zayed, his ministers and advisers.

Prince also told congress that he met Dmitriev there in a bar by chance.

But Nader is understood to have told the special counsel that the meeting was in fact brokered by the UAE to set up a back channel between Trump and Putin.

Nader's lawyer issued a statement to DailyMail.com claiming our story was 'clearly fabricated and flat out untrue'.

But the attorney and his spokeswoman declined to say what elements were untrue in any form and also refused to discuss his future travel plans.

The intrigue surrounding Nader intensified this month, when it emerged he is a convicted pedophile who had been found guilty in both the U.S. and Europe.

A Czech Republic court sentenced him to a year in prison in 2003 for ten cases of sexually abusing minors between 1999 and 2002.

In one case, Nader asked for oral sex from a 14-year-old boy in a hotel room at the Hilton in Prague.

Investigators are interested in a January 2017 meeting he reportedly helped organize in the Seychelles (pictured), the South Pacific island nation, attended by Blackwater founder Erik Prince and Zayed

Prince (pictured) claims the meeting was set up in the Seychelles to discuss counter-terrorism efforts with the Emiratis – despite the security contractor already living in Abu Dhabi near to Zayed, his ministers and advisers

When the boy refused, Nader masturbated in front of him and paid him 2,000 koruna, equivalent to around $100 today, a court official told the Associated Press.

Politico then revealed he was convicted in 1986 in a federal court in Northern Virginia in 1991 on a felony charge of transporting sexually explicit materials in foreign commerce - importing child pornography from overseas.

He also had a 1986 charge of importing from magazines depicting nude boys from the Netherlands dismissed on a technicality.

The political adviser's lawyer, Sandeep Savla, suggested details of his past had been leaked on purpose to intimidate his client.

'This is nothing more than an orchestrated, disgusting scheme by those who are trying to intimidate Mr. Nader into silence. It won't work,' he said. 'Mr. Nader will continue to answer truthfully questions put to him by the special counsel.'

Despite working as a paid adviser to Zayed, according to sources close to the Emirati prince, Nader became close to the Trump administration, has described himself as 'best friends' with former Trump chief strategist Steve Bannon, sources told DailyMail.com.

Axios reported that he frequently visited Bannon in his White House office.

The political operative even had access to information coming from the Oval Office itself according to leaked documents.

Top Trump donor Elliott Broidy wrote Nader a detailed memo of a private meeting with the president in the White House which was later leaked.

In the memo, Broidy said he lobbied Trump to increase military cooperation with the UAE and fire secretary of state Rex Tillerson.