"Complex shell companies, suspicious money transfers, links to Putin confidants and Russian oligarchs — mounting evidence Maria Butina and others may have used the NRA to try to funnel Russian [money] to the Trump campaign," Blumenthal wrote on Twitter. "NRA officials must testify — in public and under oath."
READ MORE: Maria Butina's Father Opens Up on Her Life in US
Butina was arrested in Washington DC last week on charges of acting as a Russian foreign agent, an accusation she has denied and pleaded not guilty. Butina has been denied bail and remains in custody for allegedly being a flight risk. She faces up to 15 years in jail.
US media reported Butina used the NRA to allegedly gain access to the Republican Party and to further interests of Russian officials.
The NRA is widely considered the most influential US gun-rights lobby and was a strong supporter of President Donald Trump’s 2016 campaign for the presidency.
READ MORE: 'Farce': US Authorities Trying to 'Break' Butina – Russian Ambassador
Russian officials have repeatedly denied the meddling allegations saying they are groundless and invented to deflect public attention from actual instances of election fraud, corruption as well as other pressing issues.