FPÖ leader Heinz-Christian Strache and chairman of the Vienna FPÖ Johann Gudenus are said to have joined the meeting on Saturday at Vienna’s Palais Liechtenstein.

The Tages-Anzeiger reports that the event was hosted by the Russian oligarch Konstantin Malofeew and his foundation Saint Basil the Great. Alexander Dugin, known as the chief ideologue of the Eurasian Movement, is also said to have attended the meeting.

Dugin has repeatedly called for a war of aggression against Ukraine. He was a professor of sociology at the State University of Moscow and is seen by some to have some influence on President Vladimir Putin’s thinking. Last month he referred to Austrian Eurovision Song Contest Winner Conchita Wurst as "the devil personified". 

Members of the French National Front, Marion Marechal-Le Pen, granddaughter of the party's founder and the niece of Marine Le Pen, also took part, along with right-wing politicians from Bulgaria and Croatia, according to the report.

The official theme of the secret meeting was the historic Vienna congress, which 200 years ago aimed to provide a long-term peace for Europe by settling critical issues arising from the French Revolutionary Wars and the Napoleonic Wars.

The invitation to the event elaborated on the theme, saying that today Europeans and Christians are once more faced with historical and geopolitical conditions which make it necessary to "revive the spirit of the Holy Alliance", according to Tages-Anzeiger. There was also reportedly discussion of how Europe could be saved from liberalism and the "satanic" gay lobby.

The newspaper said that the press and the public were not informed of the meeting, and that participants were sworn to secrecy. Strache is reported to have snapped a mobile phone photo at the conference table, and to have been reprimanded by the conference chairman Malofeew

Strache and Gudenus made no comment when contacted by the Austrian Press Agency about the meeting.