Former Qatari diplomat dismisses allegations from porn star's lawyer The tweets signaled an expansion of Avenatti's war of words against Cohen.

A former Qatari diplomat has confirmed that he visited Trump Tower with other Qatari officials during the presidential transition, but he dismissed allegations by adult-film star Stormy Daniels' lawyer that he met with Lt. Gen. Michael Flynn and tried to bribe other insiders for access.

In a series of bizarre tweets over the weekend, Los Angeles lawyer Michael Avenatti made unsubstantiated allegations about Ahmed al-Rumaihi that had no obvious connection to his client’s claim that she had a sexual encounter with Trump at a celebrity golf tournament in 2006.

“Why was Ahmed Al-Rumaihi meeting with Michael Cohen and Michael Flynn in December 2016 and why did Mr. Al-Rumaihi later brag about bribing administration officials according to a sworn declaration filed in court?" Avenatti tweeted, posting screen grabs of video showing Cohen and al-Rumaihi in the same lobby elevator at Trump Tower in December 2016.

In a statement sent on Tuesday, al-Rumaihi's firm Sport Trinity LLC acknowledged the visit but denied that anything improper had taken place.

“Mr. Al-Rumaihi was at Trump Tower on December 12, 2016. He was there in his then role as head of Qatar Investments, an internal division of QIA, to accompany the Qatari delegation that was meeting with Trump transition officials on that date,” the statement said. "He did not participate in any meetings with Michael Flynn, and his involvement in the meetings on that date was limited."

The tweets and subsequent TV appearances signaled an expansion of Avenatti's war of words against Michael Cohen, the President's longtime personal attorney, who facilitated a $130,000 “hush” payment to Daniels shortly before the election. Flynn was President Trump's top national security and foreign policy adviser on the campaign, during the transition and at the White House, until he was fired, prosecuted and pleaded guilty for lying to the FBI during the probe of Russian interference in the 2016 election.

Cohen did not immediately respond to a request for comment. A lawyer for Flynn did not respond to a request for comment.

Al-Rumaihi has served as a diplomat in Washington and as a spokesman for the Qatari foreign ministry, as well as representing Qatar's affiliation with Virginia Commonwealth University's School of the Arts, which has a campus in the Qatari capital of Doha.

Qatar is a key U.S. ally and hosts U.S. Central Command in Doha, but the Trump administration supported isolating Qatar last year over its alleged support of Islamist extremists. Despite that hardline policy toward the Gulf state, President Trump hosted meetings with Sheikh Tamim Bin Hamad Al-Thani, Emir of Qatar, at the White House in April.

The bribery allegation appeared to refer to a recent lawsuit filed by BIG3 basketball league advocate and rapper Ice Cube and his business partner Jeff Kwatinetz. They have alleged that al-Rumaihi invested in the sports organization in an attempt to bribe a friend of Kwatinetz -- former Trump insider Steve Bannon -- in order to gain access to and influence in Trump’s administration.

In a statement, Sport Trinity LLC forcefully denounced the lawsuit and the motivations behind it.

“Simply put, the statements in Mr. Kwatinetz’s declaration are pure Hollywood fiction," the statement reads. "Mr. Kwatinetz’s commercial dispute with Sport Trinity is meritless.”

On Monday, Avenatti continued his campaign against Cohen, telling MSNBC's Nicolle Wallace, "The issue is that you have Michael Cohen, clearly, in the weeks after the election, selling access to the president to the highest office of the land, when he's not registered as a lobbyist and he's not registered as a foreign agent.

It is a federal crime to work as an unregistered agent of a foreign government, but few have ever been prosecuted for it, and Avenatti has not offered any concrete evidence that Cohen was paid by Qatar or al-Rumahi or acted as an operative for the ruling family. Avenatti declined a request by ABC News to back up his claims.

A spokesperson for the Qatari embassy in Washington, D.C., confirmed al-Rumaihi's firm’s account of the meeting.

“Ahmed Al-Rumaihi, who was head of Qatar investments at Qatar Investment Authority (QIA) from May 2016 to March 2017, was present at Trump Tower but did not participate in any meetings, “said Jassim Al-Thani in a statement. “Since March 2017, Mr. Al-Rumaihi has not represented the State of Qatar in official matters. Nor is Qatar involved in any of his private business matters.”

The statement by al-Rumaihi's firm did not address the allegations that he boasted of bribing officials. A source close to al-Rumaihi told ABC News Special Counsel Robert Mueller’s team has not contacted the former Qatari diplomat.

A former career diplomat and U.S. Ambassador Dennis Ross told ABC News the scheme sketched out by Avenatti sounded “dizzying,” and the idea that a senior Qatari diplomat such as al-Rumaihi would try to bribe his way into the Trump orbit "doesn't seem plausible to me."

"Typically during transition periods, you have diplomats trying to go in and meet people. It's what they do," said Ross, who last served in the Obama White House after decades as a foreign service officer. "I was involved in several transition periods going back to the Reagan administration, and I had dozens of ambassadors coming in and trying to figure out what the new policies were going to be.”