A French judge is investigating former Frontex chief Fabrice Leggeri for allegedly encouraging staff to intercept migrant boats in the Mediterranean, sparking concerns over complicity in crimes against humanity.

A French judge is set to investigate former Frontex chief Fabrice Leggeri, now a member of the European Parliament for Marine Le Pen's far-right National Rally, over allegations he encouraged staff to facilitate the interception of migrant boats in the Mediterranean Sea.