One individual was found overboard and unconscious in the early hours of Friday after a boat believed to be heading for the UK got into difficulty off the coast of France
Twenty-five people were found still on board the boat and were picked up by rescue teams, while five others were found on a sandbank.
The unconscious person was taken back to shore but was declared dead.
An investigation into what happened has been opened by the Boulogne-sur-Mer prosecutor.
The latest attempts at the dangerous journey come despite sub-zero temperatures on the French coast.
Multiple Border Force vessels have been active in the Channel and at least one boat is reported to have reached the UK.
It comes after at least 271 people aboard 10 small boats reached the UK on Thursday, including a young child.
So far this year, more than 450 people have made the life-threatening trip across the Channel in small boats following a record-breaking year in 2021.
Watch: English Channel migrant crossings treble to a record 28,000