France's interior ministry said it has expelled a Swiss Islamic preacher with 'extremist' views to his home country.

The ministry said Hani Ramadan was arrested Saturday in Colmar, in eastern France, as he was taking part in a conference, and police escorted him to the Swiss border.

It said Ramadan is "known in the past to have adopted a behavior and made comments which pose a serious threat to public order on the French soil."

In 2002, Hani Ramadan was banned from teaching in a Swiss school because he had publicly defended the stoning of adulterers.

He is the brother of Islamic scholar Tariq Ramadan. The pair are grandsons of the founder of the Muslim Brotherhood, Egypt's now-banned Islamist group.