Last-minute registrations for the Brexit vote were leaning in favour of Remain at the 11th hour before a voting system crash - prompting conspiracies of a "rigged" referendum.
On what should have been the final day to register for the Brexit vote on June 7, 2016, more than 400,000 registrations were made from people under the age of 40.
This was a key demographic who were opposed to Britain leaving the EU, according to Brexit researchers Facts4EU.
However, 105 minutes before the midnight deadline, the online voter registration system crashed.
The Government was required to make a legal change in order to extend the deadline, which received the support of the Electoral Commission.
Alex Robertson, Director of Communications at the Electoral Commission, said in a statement at the time: "No one should miss out on voting in this historic referendum because of the problem with the Government’s registration website last night [June 7, 2016].
"We said this morning that legislation should be introduced to extend the registration deadline and we’re pleased the Government will now be making this change.
"We are urging everyone who is not already registered to vote to take this last chance to do so before the end of Thursday [June 9]."
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GETTY/Facts4EU
|Voting registration figures recorded on the intended 'final day' and during the extension days
The voter registration deadline was extended by 48 hours.
During that two-day extension period between June 8 and 9, 2016, a total of 436,344 more people registered to vote, Facts4EU found.
Of this total, 77.3 per cent of these people were under the age of 45, with this demographic believed to be the most likely to vote Remain.
Only 2.8 per cent of the extra votes were from those over the age of 65, an age group likely to vote in favour for Brexit.
FACTS4EU
|The number of voter registrations on the intended final day
While these numbers may show votes were working in favour of Britain staying it the EU, the referendum ultimately proved a loss for then-Prime Minister David Cameron and his fellow "Remainers".
Remain fell short of the win by just over three per cent, taking home 48.11 per cent of votes compared to 51.98 per cent for Leave.
The voting system crash could imply that the then-Government "rigged" the referendum for Remain and the gap between Brexit and Remain could have been larger if not for the technical failure, Facts4EU states.
Researchers took into account factors including that older people, likely to vote in favour of Brexit, are more likely to have already registered to vote before the final day.
FACTS4EU
|The number of voter registrations during the extended period
"For all these reasons we have applied our own statistical weightings and estimate that the final result might have been 52.2 per cent Leave and 47.8 per cent Remain", the Facts4EU report reads.
"This may not sound to statisticians like a big jump, but in the eyes of the public it would have sounded rather more decisive."
Others shared the same conspiracy at the time that the Government had rigged the vote, including Jayne Adye, who directed the Get Britain Out Campaign.
"It is clear David Cameron has been spooked by the recent successes of the Leave campaign and is now resorting to dirty tactics to encourage the last straggle of Remain supporters to register to vote", Adye said in 2016, according to The Express.
"It is deeply worrying the PM is willing to tear up our laws and conventions in order to rig the referendum."
"The Government and Remain campaigners said the high volume of vote registrations during the extension period "showed the success of intensive registration drives heightening awareness".