Authorities said on Tuesday, the day the shipwreck happened, that four suspected people smugglers had been arrested.
Gerald Darmanin, the interior minister, announced a fifth arrest on Wednesday morning. He told RTL radio station it had taken place the night before.
He called the shipwreck which killed at least 27 people a “total tragedy”.
Authorities in Lille have said 17 of the victims were men, seven were women and three were children.
Mr Darmanin told RTL on Wednesday that two survivors – one from Iraq and another from Somalia – were found in a state of hypothermia and had received treatment.