Nearly €40bn was wiped off Facebook’ share value as US markets closed yesterday.

It came after the company suffered its worst outage in more than ten years – with Facebook, WhatsApp and Instagram all down for around six hours.

Meanwhile, a whistle-blower who used to work for the company accused the company of betraying democracy in a high-profile interview on 60 Minutes.

In a blog post overnight, Facebook said the outage was due to a 'faulty configuration change' and apologised to its 3.5 billion users

It said it had no reason to believe any user data was compromised due to the outage.

“To all the people and businesses around the world who depend on us, we are sorry for the inconvenience caused by today’s outage across our platforms,” it said.

“We’ve been working as hard as we can to restore access, and our systems are now back up and running. “

The company said the root cause of the outage also affected its ability to diagnose it.

It said configuration changes to the routers that coordinate traffic between its data centres left them unable to communicate with each other properly, bringing services to a halt.

“Our services are now back online and we’re actively working to fully return them to regular operations,” it said.

“We want to make clear at this time we believe the root cause of this outage was a faulty configuration change.

“We also have no evidence that user data was compromised as a result of this downtime.”

It was Facebook’s worst outage since 2008 when a bug knocked the company’s services offline for about a day, affected 80 million users.

It was the second blow the company has faced in a week, after former employee Frances Haugen revealed herself to the whistle-blower who provided key internal company documents to the Wall Street Journal.

In an interview with 60 minutes, the former Facebook product manager accused the company of prioritizing its “own profits over public safety — putting people’s lives at risk.”

Shares in the company had fallen 4.9% when markets closed yesterday – knocking just over €40bn off the company’s value.