US Senate investigators probing Russian election interference spent more than two hours questioning President Donald Trump's senior adviser and son-in-law Jared Kushner on Monday.

Kushner briefly spoke to reporters after the closed-door meeting, denying any collusion with Russia.

"Let me be very clear: I did not collude with Russia nor do I know of anyone else in the campaign who did so. I had no improper contacts," Kushner said.

"I have not relied on Russian funds for my businesses and I have been fully transparent in providing all requested information. The record and documents I have voluntarily provided will show that all of my actions were proper and occurred in the normal course of events of a very unique campaign."

Read more: Trump son-in-law Kushner to face grilling by Congress committees over Russia ties

Kushner did not answer reporters' questions, nor did he say whether he would make public his comments to investigators. However, he said he would remain in his position as an adviser to the White House.

Before the Senate grilling, Kushner released a statement disclosing four interactions with Russians during the campaign and transition, saying he had nothing to hide. The meetings he disclosed were with then-Russian ambassador to the US Sergey Kislyak, a Russian banker close to President Vladimir Putin and a Russian lawyer said to have damaging information about Clinton.

Read more: Key figure in US, Russian Ambassador Sergey Kislyak goes home

Kushner said that Kislyak suggesting Kushner meet with banker Sergei Gorkov, who had a direct line to Putin and could provide information about what the Russian president was thinking.

"He introduced himself and gave me two gifts - one was a piece of art from Nvgorod, the village where my grandparents were from in Belarus, and the other was a bag of dirt from that same village," Kushner said of the meeting with Gorkov in December. 

Kushner also denied there was an attempt to set up a secret  "back channel" with the Kremlin and said lifting sanctions was never discussed. 

Kushner 'point of contact'

On Tuesday, Kremlin spokesman Dmitry Peskov said that the banker was not acting on Moscow's orders. Gorkov serves as chairman of Vneshekonombank, a state-owned development bank.

According to Peskov, Gorkov was visiting the US as a part of a "roadshow" and holding business meetings, part of an "absolutely normal practice" for this post.

"These contacts do not need any approval from the Kremlin and naturally (these meetings) did not happen on the Kremlin's orders," Peskov said.

In the written statement Kushner said he became a "point of contact" for foreign powers once it became clear that Trump would be the Republican presidential nominee. He wrote that he had "incoming contacts" from about 15 countries. 

The Monday appearance marks the first time a member of the president's inner circle has faced congressional investigators in the various Russia probes. Kushner was due to meet on Tuesday with the separate House intelligence committee probing Russian interference.

cw/aw/msh (AP, Reuters, AFP, dpa)