Since endorsing Donald Trump for president in July, Elon Musk – the owner of X – has posted about the US election hundreds of times, attracting more than four billion views.

BBC Verify, working with data firm Node XL, analysed all of his posts since then – over 8,000 – and searched for key words to track the election issues he has been posting about most to his 200 million followers.

Immigration and voting emerge as key themes with Mr Musk engaging with misinformation online about “illegal aliens” voting in this election.

He has also claimed repeatedly that Democrats have been “importing” immigrants who will vote for them in future elections.

But voting and immigration experts we have spoken to have challenged this, pointing out that it is illegal for them to vote in federal elections and that even if some might qualify for citizenship eventually, the process would take many years.

Mr Musk has engaged with posts on X which suggest that illegal immigrants are already voting in this election.

On 30 October, he responded to a claim that illegal voters were able to apply for mail-in ballots in Pennsylvania.

Mr Musk replied to the claim, which has been rejected by local election officials, saying: “Is this real?”

It is against the law for non-citizens to vote in US federal elections – punishment includes a year in prison, a fine, and possibly deportation.

A number of studies, both from conservative and left-leaning organisations, suggest instances of non-citizens having voted in US federal elections are very small.

Since July, Mr Musk has posted at least 22 times about voters being “imported” from abroad.

The language in many of these posts is ambiguous as to whether he means this will impact this election or future ones.

In seven posts, he has said they are going directly into swing states.

On 20 October, in a post viewed 21 million times, he said: “Triple digit increases of illegals in swing states over the past 4 years. Voter importation at an unprecedented scale!”

Along with the post, he shared a table that showed very large percentage increases in “unauthorized migrants” in Georgia, North Carolina, Pennsylvania, Arizona, Nevada, Michigan and Wisconsin, since 2021.

The table, which does not have a source, had been posted by “America” – a political action committee Mr Musk set up to support Trump.

We could not find evidence for these figures but migration experts pointed us towards the latest Department of Homeland Security report which has estimates for each state between 2018 to 2022.

These show that in several states – including Georgia, Arizona and North Carolina – the number of “unauthorised immigrants” has remained steady or dropped over this period.

They do show large numbers living in these states under the Biden administration but also when Trump was president.

Mr Musk has repeatedly suggested that illegal immigrants will gain citizenship and sway future elections for the Democrats.

In a post on 25 October, which got almost 17 million views, he said: “Their stated plan is to give them citizenship as soon as possible, turning all swing states Dem. America would then become a one-party, deep blue socialist state.”

Voting and immigration experts described this as a far-fetched claim.

Democrats have expressed a desire for some undocumented migrants in the US to have “an earned pathway” to citizenship, but it is not their stated policy to grant them all this.

“Some undocumented migrants who arrive in the US could have a route to citizenship – but that would typically take a decade or longer, if they even have a path at all, which many of them will not,” says Michelle Mittelstadt of the Migration Policy Institute.

In several posts, Mr Musk mentions a 1986 bill which granted amnesty to approximately three million undocumented immigrants in the US.

This was passed by Congress and signed into law by Republican President Ronald Reagan. It forgave individuals who came into the US illegally but did not give them immediate citizenship.

“Perhaps Musk imagines that a president or administration can simply decree mass naturalisation of noncitizens without going through the prescribed individual legal processes, and that Congress and the courts would simply then accept this. That’s not how it works”, Walter Olson, a voting rights expert from the conservative think tank, the Cato Institute told us.

On 25 October, Mr Musk posted on X: “Massive numbers flown directly to swing states and put on the fast track to citizenship. Voter importation.”

The post, viewed almost 19 million times, included a chart entitled “inadmissible aliens” shared by Mario Nawfal.

Mr Nawfal has been community noted (the process on X which crowdsources fact-checking from users) several times for making unverified claims.

He is one of the people Mr Musk has interacted with most on X over the last few months, according to Node XL.

It is unclear where the figure of 823,000 “inadmissible aliens” comes from.

The chart refers to @fentasyl – the anonymous X account of a “data expert” – but does not have a source.

It shows a large increase in migrants from Venezuela, Nicaragua and Haiti entering the US from 2023 onwards.

This appears to be a reference to the Humanitarian Parole Scheme launched in January 2023. This scheme allows vetted migrants from Cuba, Haiti, Nicaragua, and Venezuela to live and work in the US legally – if they have a US sponsor.

Big numbers have arrived under this scheme – 531,000 people up until the end of September 2024.

But they are not allowed to vote and are not put on “a fast track to citizenship”.

They are permitted to stay in the US for a maximum of two years.

Some may be able to apply for protected status which would allow their temporary stay to be extended. But, even if they got this, they would not be able to vote in a federal election.

Those who do not qualify have to leave the country or face deportation proceedings.

“There is no direct path to a green card for people entering the US from Nicaragua, Venezuelan or Haiti on the Humanitarian Parole Scheme,” says Ms Mittelstadt.

“They could apply for asylum but these claims can take years, and if granted it doesn’t give you the right to vote,” she adds.

To become a US citizen – and get the right to vote in a federal election – you have to go through naturalisation.

To apply, someone has to have been a lawful permanent resident for five years; married to a US citizen and a lawful permanent resident for three years; or be a member of the military.

As of August 2024, 3.3 million immigrants had become naturalised citizens under the Biden administration.

Under Trump, the figure was around three million people.

It is also worth noting that new citizens are not guaranteed Democratic voters.

According to a recent survey, 54 percent of naturalised citizens said they would vote for Harris in November, while 38 percent said they would vote for Trump.

We have asked X for comment and to provide further evidence for Mr Musk’s claims.