Donald Trump
President Donald Trump's official Twitter account was registered to a non-government email address for a weekAlex Wong/Getty Images

President Donald Trump's official @POTUS Twitter account was linked to a potentially insecure private Gmail address for the past week, raising serious concerns about the digital security of one of the most powerful Twitter accounts in the world. The account registration was changed on Thursday (26 January) after multiple observers flagged the potential vulnerability on Twitter. It is now linked to two different White House email addresses.

TV Guide's managing editor Alex Zalben brought up the issue after noticing the registration on Twitter.

"Seven days!" Zalben tweeted in a series of posts. "SEVEN DAYS, they've had the President's Twitter account attached to a PERSONAL E-MAIL ADDRESS."

"I THINK there was some sort of discussion about unsecured, personal e-mail addresses being used for government business during the campaign," he continued.

During the race to the White House, Democratic candidate Hillary Clinton drew sharp, widespread criticism, particularly from the Trump campaign, over her using a personal email account while she was US secretary of state.

Since Twitter only shows the first two characters of a person's email address, it is difficult to definitively know whom the Gmail address belongs to. The personal Gmail address is believed to belong to White House social media director Dan Scavino.

Anyone with access to the private Gmail account would have been able to request the password for the closely watched @POTUS account and make unauthorised tweets. During the presidential election campaign, Trump frequently used Twitter to get his message directly to voters, attack his rivals, make announcements and criticise the mainstream media.

His tweets about public companies have also been shown to move stock prices.

The incident comes after The New York Times reported Trump was still using his Android smartphone, despite serious objections and concerns from aides and security experts.

Earlier this week, a hacker going by the name WauchulaGhost - who previously breached around 500 pro-Isis Twitter accounts - said the president, Vice President Mike Pence and First Lady Melania Trump's Twitter accounts were not using some available security settings on the microblogging site — two-step verification.

As a result, WauchulaGhost told CNN that anyone can see a partially redacted version of the email address associated with each account.

"It's not hard to figure the e-mails out from there," WauchulaGhost said. "Once the email is exposed there is a chance it can be compromised. That's the issue."

The hacker also tweeted out the email addresses associated with the Twitter accounts of the first lady, press secretary Sean Spicer and Scavino.

"All I have to do is guess the email. Which I have been rather good at doing. Then verify the email exists. At that point take the email account, reset Twitter password, boom....I own the pres. Not saying I'm going to...haha. But it's rather easy for some."

Earlier this week, Newsweek reported that many of Trump's top advisers, including chief strategist Steve Bannon, senior advisers Kellyanne Conway and Jared Kushner as well as Spicer were using private accounts on a Republican National Committee (RNC) system until Wednesday (25 January) - the same one that George W Bush's administration was accused of using to dodge transparency rules.