The private messages and email addresses of Irish people who joined an online forum used by neo-Nazis and fascists have been published online following an attack by an unidentified hacker who used the name “antifa-data”.

The leaked database contained the user names, IP addresses, private messages, public posts and emails used by people based in Ireland to register accounts with IronMarch, a now-defunct forum for far-right extremists.

IronMarch was purportedly founded by a Russian nationalist in 2011 but closed in late 2017 amid concerns about its support for genocide and terrorism. Users of the site have been linked to murder and attacks on immigrants.

Some of the Irish-based users discussed their support for fascism and questioned the reliability of the media, according to leaked messages.