Twitter has warned that private messages sent and received on its Android app may have been exposed to the public for years.

A recently discovered security flaw led to ‘protected’ messages being made public if users updated the email address linked to their account.

Twitter said it did not know exactly how many people have been impacted, but Twitter users who altered their email address between November 2014 and January 2019 may have been affected.

Twitter says it fixed the error on the 14th of January and has begun contacting users it believes to be at risk. It has also issued a public warning as it cannot confidently pinpoint all those affected.

Users who accessed Twitter via the website or through an Apple device are not at risk.

A spokesperson for the social media network said: “We’re very sorry this happened and we’re conducting a full review to help prevent this from happening again.”

Twitter users should check their privacy settings to ensure they reflect their preferences, the spokesperson added.

It encouraged users to check their privacy settings to make sure they reflected their preferences.

In September 2018, Twitter fixed a bug that shared the direct messages and protected tweets of some users with developers who were not authorised to access them.