Security researchers have found that the private browsing modes on most web browsers leak user data.
Private browsing mode is designed to automatically delete all the logs of the websites that have been visited by the user in this mode.
The researchers found, however, that web browsers on private browsing mode were capable of logging information by other means.
The research, which was carried out by experts at the Stanford and Carnegie Mellon University, examined the four most popular browsers that offer private browsing - Firefox, Chrome, Internet Explorer and Safari.
It was found that plug-ins and add-ons installed on web browsers were capable of recording a user's web activity despite private browsing mode being activated.
The researchers also found that security mechanisms utilised by some websites monitored the information exchanged between the website and a user's computer.
The research will be presented by the security experts during the Usenix security conference set to take place in Washington D.C from 11 August.