The US Securities and Exchange Commission (SEC) is investigating a fake online news story that claimed Twitter had received a $31bn buyout offer.

Shares in the micro-blogging website increased approximately 8% following the report, which appeared on the fake news site named bloomberg.market.

The post’s design was similar to the Bloomberg site, prompting investors to believe the story. However, Twitter and Bloomberg later clarified that the story was fake.

Bloomberg spokesman Ty Trippet said: "The story was fake and appeared on a bogus website that was not affiliated with Bloomberg."

The news agency noted that the website carrying the fake report was registered on 10 July to a post office box in Panama belonging to WhoisGuard.

Twitter was subject to speculations on a potential takeover bid since the resignation of its former CEO Dick Costolo due to disappointing financial results.

Costolo served as CEO for five years. Twitter’s co-founder Jack Dorsey was named as interim CEO.

The company is struggling to both attract advertisers and draw new users.