Elon Musk has donated $75m (£58m) to a campaign group he set up to support Donald Trump’s presidential bid.
The donation to America PAC, which was made in several payments over the summer, has been revealed in new campaign finance disclosures.
Around $72m (£56m) of the $75m (£58m) has already been spent by the group on canvassing efforts to encourage people to vote.
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America PAC has been hit by problems with hiring campaigners in recent months, having fired two major contractors since July who were tasked with knocking on front doors.
Following the disclosure, Musk wrote on social media that America PAC was “just aiming for common sense, centrist values”.
The billionaire previously supported the Democrats but has become a vocal backer of Mr Trump in recent months.
He has vowed to help with campaign efforts and joined the Republican candidate on stage at a campaign rally earlier this month in Pennsylvania.
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Elon Musk joins Donald Trump on stage
At the event, Musk – who runs Tesla and SpaceX – jumped around on the stage and described next month’s presidential election as a “must-win situation” during brief remarks to the crowd.
Mr Trump has welcomed Musk’s support and described him as someone who is “as smart as you get”.
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There has been intense speculation over Musk’s contributions to the Trump campaign, after the Republican presidential candidate claimed in July that Musk gave him “$45m a month”.
The billionaire disputed the figure and later tweeted his donations were “at a much lower level”.
America PAC is one of several major political action committees in the US.
Such groups can raise and spend unlimited amounts of money in support of political candidates, on the condition that they do not co-ordinate with their campaigns or give money to them.
America PAC has declined to comment on the donations.
Musk is currently the world’s richest man, with an estimated net worth of $248bn (£191bn), according to Forbes.