WASHINGTON -  Hillary Clinton is being urged by computer scientists and lawyers to challenge the presidential election results in three key swing states, two of which Donald Trump won two weeks ago.

The group believes it found evidence that vote totals in the three states-Michigan, Pennsylvania and Wisconsin-might have been affected by a cyberattack, saying the Democratic nominee received 7 percent fewer votes in counties that relied on electronic-voting machines instead of paper ballots or scanners, New York magazine reported.

But the professor who posted online, J. Alex Halderman of the University of Michigan (who also directs the Center for Computer Security and Society), said the most likely explanation for Trump’s win is that the polls “were systematically wrong.” Most pre-election polls indicated Clinton would win the presidency.

Trump defeated Clinton in Pennsylvania and Wisconsin, and while the billionaire businessman is ahead of the Democrat in Michigan, the state’s results are not yet final.

Halderman also argued that a foreign government could have probed certain election offices prior to November 8 to find ways to break into computers and ultimately spread malware into voting machines in states where polling data showed close electoral margins.

The Obama administration has publicly accused the Russian government of directing hacks to influence the election, including leaking emails from the Democratic National Committee and from several individual accounts, such as that of Clinton campaign Chairman John Podesta.

The group, which is urging Hillary Clinton’s campaign to join its fight, is preparing to deliver a report detailing its concerns to congressional committee chairs and federal authorities early next week, according to two people involved.

“I’m interested in verifying the vote,” said Dr Barbara Simons, an adviser to the US election assistance commission and expert on electronic voting. “We need to have post-election ballot audits.” Simons is understood to have contributed analysis to the effort but declined to characterise the precise nature of her involvement.

The developments follow Clinton’s surprise defeat to Donald Trump in the 8 November vote, and come after US intelligence authorities released public assessments that Russian hackers were behind intrusions into regional electoral computer systems and the theft of emails from Democratic officials before the election.

Having consistently led Trump in public opinion polls for months preceding election day in all three midwestern states, Clinton narrowly lost Pennsylvania and Wisconsin, and may yet lose Michigan, where a final result has still not been declared.

Curiosity about Wisconsin has centred on apparently disproportionate wins that were racked up by Trump in counties using electronic voting compared with those that used only paper ballots. The apparent disparities were first widely publicised earlier this month by David Greenwald, a journalist for the Oregonian.

However, Nate Silver, the polling expert and founder of FiveThirtyEight, cast significant doubt over this theory on Tuesday evening, stating that the difference disappeared after race and education levels, which most closely tracked voting shifts nationwide, were controlled for.

Silver and several other election analysts have dismissed suggestions that the swing state vote counts give cause for concern about the integrity of the results.

Still, dozens of professors specializing in cybersecurity, defense, and elections have in the past two days signed an open letter to congressional leaders stating that they are “deeply troubled” by previous reports of foreign interference, and requesting swift action by lawmakers.

“Our country needs a thorough, public congressional investigation into the role that foreign powers played in the months leading up to November,” the academics said in their letter, while noting they did not mean to “question the outcome” of the election itself.

According to current tallies, Trump has won 290 Electoral College votes to Clinton’s 232, with Michigan’s 16 votes not apportioned because the race there is still too close to call. It would take overturning the results in both Wisconsin (10 Electoral College votes) and Pennsylvania (20 votes), in addition to winning Michigan’s 16, for Clinton to win the Electoral College. There is also the complicating factor of “faithless electors,” or members of the Electoral College who do not vote according to the popular vote in their states. At least six electoral voters have said they would not vote for Trump, despite the fact that he won their states.

The Clinton camp is running out of time to challenge the election. According to one of the activists, the deadline in Wisconsin to file for a recount is Friday; in Pennsylvania, it’s Monday; and Michigan is next Wednesday. Whether Clinton will call for a recount remains unclear. The academics so far have only a circumstantial case that would require not just a recount but a forensic audit of voting machines. Also complicating matters, a senior Clinton adviser said, is that the White House, focused on a smooth transfer of power, does not want Clinton to challenge the election result. Clinton communications director Jennifer Palmieri did not respond to a request for comment. But some Clinton allies are intent on pushing the issue. On Wednesday, Huma Abedin’s sister Heba encouraged her Facebook followers to lobby the Justice Department to audit the 2016 vote. “Call the DOJ…and tell them you want the votes audited,” she wrote. “Even if it’s busy, keep calling.”