Twitter has identified a scheme that uses compromised file-sharing sites to steal the log on information of users.

The service said it had discovered a number of compromised "torrent" sites that had been set up specifically to skim usernames and passwords.

Torrent sites acts as indexes of links to TV, film and music files.

Scammers were then able to use the data to gain access to Twitter and other sites because many people use the same logon for multiple services.