Elon Musk has denied reports that he was donating $45 million a month to a fund backing former US president Donald Trumps latest White House bid.

In a Tuesday post on X, Musk called the report he was funding a so-called political Super-PAC ridiculous.

Super PACs are specially designed groups that can spend unlimited amounts on political candidates and causes.

I am making some donations to America PAC, but at a much lower level and the key values of the PAC are supporting a meritocracy & individual freedom.

Republicans are mostly, but not entirely, on the side of merit & freedom, he added.

Musks comments came days after the democratic campaign for the presidential election was re-invigorated with Vice President Kamala Harris stepping in for Joe Biden.

The Wall Street Journal had reported that Musk plans to donate $45 million monthly to America PAC, even though Musk stated just months ago that he would not donate to either Trump or President Joe Biden.

The Tesla founder formally endorsed Trumps candidacy for US president earlier this month immediately after the Republican survived a shooting at a political rally in Butler, Pennsylvania.

Musk is one of several major backers of the new fund, with others reportedly including Palantir co-founder Joe Lonsdale, former US ambassador to Canada Kelly Craft and cryptocurrency investors Tyler and Cameron Winklevoss. (AFP)