Several prominent computer scientists and attorneys are pushing Hillary Clinton to seek a recount in three key swing states that cost her the election, suggesting that statistical irregularities in results from counties that used electronic voting machines indicate the possibility of manipulation or hacking.

The states in question are Michigan, Wisconsin, and Pennsylvania, which combined to give Donald Trump 46 votes in the electoral college, propelling him to an upset victory over Clinton. According to New York magazine and CNN, several experts, including J. Alex Halderman, the director of the University of Michigan’s Center for Computer Security and Society, have contacted the Clinton campaign and presented evidence that she may have been denied votes in several counties in these states.

The reports say Clinton received 7 percent fewer votes in Wisconsin counties that used electronic voting, a statistically significant margin that could have tipped the state — which hadn’t been won by a Republican presidential candidate since 1984 — in Trump’s favor. Clinton lost Wisconsin by 27,000 votes, but the experts reportedly say that with the alleged irregularities she may have been denied up to 30,000 votes.

“The only way to know whether a cyberattack changed the result is to closely examine the available physical evidence — paper ballots and voting equipment in critical states like Wisconsin, Michigan, and Pennsylvania,” Halderman wrote in a Medium post Wednesday. “Unfortunately, nobody is ever going to examine that evidence unless candidates in those states act now, in the next several days, to petition for recounts.”

Clinton only has until Friday to seek a recount in Wisconsin, and until early next week to challenge the results in Pennsylvania and Michigan, but the Department of Justice could move to investigate the situation even after the fact. After Russian hackers were accused of targeting the Democratic National Committee ahead of the election, U.S. authorities, including the Pentagon, the CIA, and other intelligence agencies, were reportedly closely monitoring the situation on Election Day for anything unusual.

The sister of top Hillary Clinton aide Huma Abedin has urged her Facebook followers to contact the Department of Justice and request an investigation into possible voting irregularities in the three swing states. Abedin said Clinton would only need a shift of about 55,000 votes in the states to win the election.

Abedin wrote that federal authorities “are starting to recognize there really is something off about the election results… Considering everything that is at stake, a vote audit should be done.”