Tech billionaire Elon Musk has donated about $119 million to support Republican Donald Trump’s presidential election campaign.

By mid-October, the Tesla boss had transferred $43.6 million to America PAC, primarily focused on winning hotly contested swing states such as Pennsylvania.

Between July and the end of September, Mr Musk, who has also appeared at numerous Trump rallies, donated about $75 million.

Meanwhile, America PAC is continuing its controversial daily giveaway, handing 1 million dollars per day to one registered voter at a time.

On Wednesday, the U.S. media reported that the U.S. Department of Justice warned Musk that the campaign could violate electoral law.

The campaign is set to run until November 5 and is aimed at registered voters who sign a petition.

The petition is about “freedom of speech and the right to bear arms.”

According to the U.S. election law, paying citizens money to vote or registering to vote is illegal.

Mr Musk argued that the million-dollar gift is intended to attract more attention to the petition and is, therefore, legal.

Mr Trump is running to be president against Democratic candidate, Vice-President Kamala Harris, in what polls show will be a tight race for the White House.

(dpa/NAN)