The United Nations says a member of the U.N. panel of experts monitoring sanctions against Libya has been arrested in Tunisia despite having diplomatic immunity.

U.N. deputy spokesman Farhan Haq said Mocef Kartas, who reportedly has dual German-Tunisian citizenship, was arrested following his arrival in Tunis on March 26.

Haq told reporters Friday that the U.N. has asked Tunisian authorities about the reasons for his arrest and the conditions under which he is being held.

He said the U.N. also informed authorities that "experts on mission for the United Nations, as Mr. Kartas is, are covered by the convention on the privileges and immunities of the United Nations."

Secretary-General Antonio Guterres will be attending the Arab League summit in Tunis this weekend.