A group of computer security experts are banding behind Green Party leader Jill Stein's demand for a manual recount of votes in three US states, citing suspicion of foreign hacking in order to manipulate the vote.

Stein is now suing Wisconsin to be able to conduct a recount by-hand after the state's Election Commission said Monday (28 November) that decision should be left to each county.

However, "it would send the incorrect signal if we were not to review the voter-verified paper records of the election," said Poorvi Vora, an electronic voting system expert and computer science professor at The George Washington University. She was considering "the unhealthy interest demonstrated by foreign powers in influencing the 2016 presidential election," she said.

Vora made her case in an affidavit supporting Stein that was submitted to the Wisconsin Dane County circuit court. She said it's nearly impossible to pick apart lines of malicious computer code from voting machine systems.

Evidence has emerged that a host of hacks on the Democratic party and voter registration system were perpetrated by Russian intelligence affiliated groups during the summer and fall.

USA-ELECTION/Jill Stein
Green Party leader Jill Stein in Philadelphia, Pennsylvania, July 25Reuters/Bryan Woolston

"Our election systems face credible cyber-threats generally and, in this election year, those threats are magnified in light of the persuasive evidence of state-sponsored attacks against our elections," wrote Dan Wallach, a computer science professor and member of the Baker Institute for Public Policy at Rice University, in an affidavit supporting Stein.

A crucial feature of an audit "is that paper ballots are inspected directly by humans and not merely tabulated again by a machine," wrote Walter R Mebane Jr, a professor of statistics at the University of Michigan. In a 27 November article, Mebane points out "anomalies" in the vote in areas of Wisconsin that used Opscan technology.

vote counting
Counting votes is a long and tedious processReuters

The article was submitted as evidence for Stein's case by Professor Philip Stark, director of statistical computing at the University of California, Berkeley.

Stein has raised a total of $6.4m in a bid to conduct recounts in three states, including Wisconsin, Pennsylvania, and Michigan, where President-elect Donald Trump won by a combined margin of just 107,000 votes. Her attempt to launch this unprecedented effort, however, is coming up against a series of walls. She believed the Wisconsin recount would cost $1.1m, but the figure is more like $3.5m. The money needs to be handed over to officials by the end of Tuesday (29 November).

The recount campaign was prompted by initial concerns raised by Cybersecurity expert J Alex Halderman and constitutional law and voting rights lawyer John Bonifaz who said statistical data indicates the vote may have been manipulated.

At a news conference Wisconson's Election Commission chair Mark Thomsen said that he fully expects that "the outcome is not going to be different." Officials have said they see no anomalies in vote data.

Trump continued to needle Stein's quest to mount a recount Monday by questioning the validity of the entire election and falsely claiming that he would have won the popular vote if more than a million immigrants hadn't voted illegally.

During a daily phone call Monday Trump's transition team said that the recount is a "scam by the Green party" and that it is "just a way for Jill Stein... to fill her coffers with money."