A mystery rooted in President Donald Trump's claim that he was wiretapped by then President Barack Obama during the 2016 election campaign has deepened with the disclosure that a top congressional Republican reviewed classified information about the charge on the White House grounds.
In a separate development, Trump's son-in-law, Jared Kushner, a top White House adviser, has volunteered to testify before the US Senate Intelligence Committee's investigation into whether Russia attempted to interfere in the November 8 US election, a White House spokesman said.
Russia state development bank VEB confirmed that its executives held talks with Kushner, RIA news agency reported on Monday.
The meetings took place "in the format of a strategy development roadshow", the agency said.
Devin Nunes, chairman of the House of Representatives Intelligence Committee, visited the White House the night before announcing on Wednesday that he had information that indicated some Trump associates may have been subjected to some level of intelligence activity before Trump took office.
Nunes spokesman Jack Langer said in a statement that Nunes "met with his source at the White House grounds in order to have proximity to a secure location where he could view the information provided by the source."
Nunes told reporters on Wednesday that he had briefed Trump "on the concerns I had about incidental collection and how it relates to President-elect Trump and his transition team and the concerns that I have."
After an uproar over the allegations and the fact that he briefed Trump first before members of his own committee, Nunes apologised on Thursday for the way he handled the information.
A congressional source said congressional investigators have questioned agencies directly to try to find out what intelligence reports and intercepts Nunes is referring to, but that as of Monday the agencies were still saying they did not know what Nunes was talking about.
The Washington Post reported on Monday that Nunes was on his way to an event late Tuesday when he left his staff and went to review classified intelligence files brought to his attention by his source, whom he has not identified.
