“Foreign parties, state actors and, potentially, others interested in affecting US political processes need anonymity,” said Scott Dueweke, a cybersecurity consultant in Washington, said at a Senate Judiciary subcommittee hearing.

“The exchange of digital assets can occur without the need for a central issuing authority,” he added, making them “tailor-made for money laundering.”

Virtual currencies were not as accessible or as widely used when Russians meddled in the US presidential election in 2016, but now should be considered a potentially formidable weapon in the arsenal of those wishing to confuse voters or disrupt the vote, witnesses and senators said.

The hearing took place as several states held primary and runoff contests and as election authorities around the US are trying to protect their systems ahead of November general elections.

Senator Sheldon Whitehouse, Rhode Island Democrat, said cryptocurrency and shell companies are open pathways for foreign interference in American elections.

” Vladimir Putin and his oligarchs can use the exact same tactics that American special interests use to spend anonymous money in our elections and secure influence,” Whitehouse said.

“Russia has been able to leverage these virtual currencies,” Dueweke said.

Senator Lindsey Graham, a South Carolina Republican and the subcommittee chairman, said shell companies could allow foreign interests to anonymously exert their power through election spending.