WASHINGTON (Sputnik) — The senators said they were concerned about Sessions' failure to accept responsibility "for testimony that could be construed as perjury," the letter added.
"We ask that you investigate all contact the Russia ambassador, or any other Russian officials, may have had with Attorney General Sessions or his staff, and whether any laws were broken in the course of those contacts or in any subsequent discussion of whether they occurred," Leahy and Senator Al Franken said in one of the letters.
The requests were sent on March 20, April 28 and May 12. The last letter was addressed to Acting FBI Director Andrew McCabe.
In March, Sessions recused himself from the probe into President Donald Trump's connections with Russia after the Washington Post reported that he held two meetings with Kislyak, despite denying contacts with Kremlin officials at his confirmation hearing.
Moscow called the allegations untruthful and repeatedly denied making any attempts to sway the 2016 US presidential election in Trump's favor. Kremlin spokesman Dmitry Peskov said the Russian government had no official contacts with Trump's campaign. Trump also called the investigation a with hunt and underlined that he would like the probe to be concluded as soon as possible.