Radical feminist group Femen has responded to the public suicide of a 78-year-old far-right author by staging a topless demonstration in Paris's most famous cathedral.

A lone activist staged a fake suicide in the Notre Dame cathedral, before she was arrested by French police.

With the words "May fascists rest in hell" emblazoned across her naked chest, the woman pointed a fake gun into her mouth next to the altar.

The demonstration came a day after right-wing writer Dominique Venner shot himself through the mouth in front of the same ceremonial table.

Before going to Notre Dame, Venner posted on his blog a damning critique of the same-sex marriage bill recently approved by the French parliament, and called for "spectacular and symbolic actions [to] awaken consciences".

His suicide was described as "political" by far-right French politician Marine Le Pen, a vocal critic of the same-sex marriage bill pushed by President Francois Hollande.

"All our respect to Dominique Venner, whose last and deeply political gesture has been an attempt to awaken the people of France," Le Pen, president of the Front National (FN) party, tweeted.

In a provocative statement, Femen called for all "European Nazis" to follow Venner's example and commit suicide, "thereby permanently excluding themselves from the political arena in Europe".

"Hurry, on the sacrificial altar of Notre Dame, there is not so much space!" the group wrote on its website.

A former paratrooper, Venner was a member of the Secret Army Organisation (OAS), which sought to keep Algeria under French control and in the early 1960s tried to assassinate former president Charles de Gaulle.

The group also urged authorities to prosecute Le Pen for praising Venner's public suicide.

Femen, which has carried out a number of high-profile protests across Europe, including topless marches in Paris and an ambush of Silvio Berlusconi, has recently raised controversy in Tunisa where one of its affiliates was arrested earlier this week for protesting outside a mosque.