Millions of pounds worth of cryptocurrency could be at risk following the disclosure of a major chip flaw which could leave the passwords and private keys that are used to secure online transactions open to thieves.

The Meltdown and Spectre vulnerabilities, which were confirmed on Wednesday evening, could be exploited by hackers to steal huge amounts of cryptocurrency until they are patched, security experts have warned.

Many online services that use a shared cloud could potentially be at risk, but Bitcoin and other cryptocurrency exchange sites will be a particular target as it is easier to steal from them than a bank.

The bugs affecting Intel, AMD and ARM processors are understood to be present on billions of devices, including cloud providers, which many cryptocurrency providers rely on to keep their businesses running.

"The most obvious use of Spectre and Meltdown is to dump cryptocurrency private keys and steal wallet passwords without having to send out ransomware, thus gaining instant profit," Matt Carr, security consultant at Insinia told the Telegraph.

"I think we will see people exploiting this to steal Bitcoins."