As many as 33 million Twitter usernames and passwords have reportedly been put on sale online, said a report.

According to a report on LeakedSource, a Russian hacker - who goes by the name Tessa88 - claims to be in possesion of a database containing email addresses, passwords and usernames of about 10 per cent of Twitter's monthly active users.

The explanation for this is that tens of millions of people have become infected by malware, and the malware sent every saved username and password from browsers like Chrome and Firefox back to the hackers from all websites including Twitter.

The data is being sold for 10 Bitcoin, which is is roughly about $5,775.

Twitter said Wednesday the data hadn't come from a breach and was working with users to protect their accounts.