Ógra Shinn Féin (the youth wing of the party) super-imposed the MP's head on the body of a man in Nazi regalia.

It also published a photograph of Mr Campbell beside Nazi propaganda minister Joseph Goebbels.

The picture has actually been on the site since July, after Mr Campbell became culture minister.

Republicans said his appointment was akin to making French National Front leader Jean Marie Le Pen head of race relations in France, because of the DUP man's record of opposition to an Irish Language Act and support for Glasgow Rangers.

Mr Campbell said he was "quite happy Sinn Féin are unhappy with me" but a boundary had been crossed.

The culture minister added: "The irony will not be lost on people that this is the youth wing of an organisation that has had fascist tendencies calling a democrat a fascist."

Sinn Fein MLA Barry McElduff said he would pass on the comments to his party colleagues.

Republicans often use derogatory comparisons, between Protestants/unionists and Nazis. Protestants are known as "Huns".

And just a few years ago, even the Irish President Mary McAleese compared Protestant treatment of Roman Catholics in Northern Ireland, to the Nazis' treatment of the Jews.

She later had to apologise.