"Any intelligence out there that suggests that somebody is of interest to us, we have to pursue it," Burr said. "We've now got an email chain that makes that (the meeting) a very important aspect to get into."
Senator Mark Warner, the panel's Democratic vice-chairman, said some of the questions he wanted answered were: "Why were all those individuals there? What was really the purpose? What was the discussion?"
Special Counsel Robert Mueller and congressional panels are investigating allegations by US intelligence agencies that Russia interfered to help Trump win the presidency.
An American-based employee of a Russian real estate company took part in the June 2016 Trump Tower meeting, bringing to eight the number of known participants at the session.
Ike Kaveladze's presence was confirmed by Scott Balber, a lawyer for Emin and Aras Agalarov, the Russian developers who hosted the Trump-owned Miss Universe pageant in 2013. Balber said Kaveladze works for the Agalarovs' company and attended as their representative.
Balber said that he received a phone call from a representative of Mueller over the weekend asking if Kaveladze would agree to be interviewed. Balber said his client would cooperate. The request is the first public indication that Mueller's team is investigating the meeting.
Rob Goldstone, a music promoter, told Trump jnr in an email that his client, Emin Agalarov, a Russian pop star, requested that Trump jnr meet the lawyer.
The full list of the participants has remained a mystery until now, despite a statement from Trump jnr that he was releasing his emails in an effort to be "transparent" about the meeting, which he has said amounted to nothing.
Balber said Kaveladze works as a vice-president focusing on real estate and finance for the Agalarovs' company, the Crocus Group. Aras Agalarov requested that Kaveladze attend the meeting on his behalf, Balber said. Kaveladze is a US citizen and has lived in this country for many years, according to Balber, who said he is representing the man.
Balber said Kaveladze believed he would act as a translator, but arrived to discover that the lawyer, Natalia Veselnitskaya, had brought her own translator, a former State Department employee named Anatoli Samochornov. Samochornov has declined to comment, citing a non-disclosure agreement he signed as a professional translator. Balber said he believes the list of participants known to the public is now complete.
Other participants in the meeting were Jared Kushner, the son-in-law of the President, and Paul Manafort, a top campaign aide, as well as Rinat Akhmetshin, a Russian American lobbyist who was lobbying to lift sanctions imposed in 2012.
Born in the Soviet Republic of Georgia, Kaveladze came to the United States in 1991. According to his LinkedIn profile, he holds a business degree from the University of New Haven.
In 2000, Kaveladze's actions as the head of a Delaware company called International Business Creations were the subject of a government investigation into how Russians and other foreigners were able to launder large amounts of money through US banks.
The GAO report, which had been requested by Congress, concluded that it was "relatively easy" for these foreigners to use shell companies to open US banks accounts and route hidden money through the American financial system.
The report described the activities of IBC's president, who Balber confirmed was Kaveladze.
Balber said Kaveladze was not charged with any crime as a result of the inquiry, which he said was largely focused on the internal procedures of US banks.
"There has never been any indication that he did anything wrong," Balber said. "From his perspective, it was a big nothing."
According to the GAO, Kaveladze opened 236 bank accounts in the US for corporations formed in Delaware on behalf of mostly Russian brokers. Kaveladze told officers of two US banks that he had conducted investigations of the Russian companies for which he opened accounts. However, he told GAO investigators that was not truthful.
"He admitted to us that he made such representations to the banks but that he in fact had not investigated the companies," the report said.
All told, the report traced the movement of US$1.4 billion in wire transfer transactions deposited in to 236 accounts opened at the two banks, Citibank and Commercial Bank.
The report said that IBC and an associated firm established those accounts and that more than US$800 million was wired from foreign countries in to IBC-related accounts.
- additional reporting AP
