Facebook is to hand over the contents of over 3,000 adverts as part of an investigation into claims of interference in the US presidential election.

They're all believed to have originated from fake accounts linked to Russia.

In a blog post, Facebook says: "We believe it is vitally important that government authorities have the information they need to deliver to the public a full assessment of what happened in the 2016 election.

"That is an assessment that can be made only by investigators with access to classified intelligence and information from all relevant companies and industries - and we want to do our part.

"Congress is best placed to use the information we and others provide to inform the public comprehensively and completely."

Facebook Elections signs stand in the media area at Quicken Loans Arena in Cleveland before the first US Republican presidential debate | Image: John Minchillo / AP/Press Association Images

US special counsel Robert Mueller is investigating alleged Russian interference in the 2016 presidential election.

Moscow denies any meddling and US President Donald Trump has denied collusion by his campaign.

The social media giant's chief executive, Mark Zuckerberg, says they're working to create more transparency:

 Additional reporting: Jack Quann