An Egyptian-born Swiss Muslim cleric was expelled from France on Saturday for past remarks and behaviour that posed a serious threat to public order, the French Interior Ministry said in a statement.

Hani Ramadan was arrested in Colmar, in northeastern France, where he was expected to take part in a conference.

"Interior Minister Matthias Fekl, ordered Hani Ramadan to be returned to Switzerland this evening," the statement said.

Ramadan is known to have spoken and behaved in a way that posed a serious threat to public order, it said.

France is under heightened alert following a spate of attacks by Islamist militants since January 2015 that have killed more than 230 people.

The threat posed by radical Islamist militants is a hot button in the French April-May presidential election