An Austrian far-right group has leaked documents stating an undercover army intelligence agent who defaced a mosque in Graz with a pig’s head was really meant to infiltrate the hipster-right Identitarian youth movement.

The Austrian far-right neo-nazi group Unwiderstehlich or “Irresistible” in English, have published files from the Klagenfurt Public Prosecutor’s Office, according to the Austrian Ministry of Defence, Der Standard reports.

Most of the substance of the documents revolves around an incident in Graz in May 2016 when a pair of pig heads were found at the site where a new mosque was being built in the city.

A few months later, reports came out that one of the people involved in the act was an Austrian army intelligence agent who was sent to infiltrate right-wing groups. Army staff in Graz who worked with the man claimed to have had prior knowledge of the plan to deface the mosque yet took no action to stop it.

The Ministry of Defence confirmed the leaked documents were genuine but did not disclose who they thought had sent the information to the neo-Nazi group. Der Standard has speculated that the accused in the case, or his lawyer who has access to the documents, may have copied the report.

Austrian Defence Ministry spokesman Michael Bauer has described the situation as “suboptimal” and the public prosecutor’s office Klagenfurt had no idea the documents had even been leaked until approached by the media.

The real target for the arrested Austrian intelligence officer was not the group who carried out the mosque incident, but rather the Identitarian youth movement. He was paid 100 euros to infiltrate them and attend their annual summer camp in France.

Weeks before the pig heads incident, the Identitarians had intended to protest the building of the mosque but protested the headquarters of the far-left Green Party instead.

The Identitarians have become well known in Austria for their protests against Islamisation and mass migration which have included putting a burqa on a statue of Austria’s only Empress Maria Theresa and hoisting a banner on the top of the Burgtheater during a pro-migrant play.

In neighbouring Germany, the intelligence services have long made it public they are monitoring the group, claiming to have evidence of “efforts against the free democratic basic order”.

Co-leader of the Austrian Identitarians Martin Sellner told Breitbart London at the time: “We think that the intelligence service should rather watch the radical Islamists that Merkel invited to Europe, rather than young men and women who fight against Islamisation.”