Another migrant is understood to have died while trying to cross the English Channel to reach the UK.
It comes as more than 30,000 migrants are believed to have arrived in the UK after crossing the Channel so far this year.
At least one person is thought to have lost their life while attempting the journey on Wednesday, sources told the PA news agency.
The French coastguard, understood to be attending the incident, has been contacted and further details are yet to be confirmed.
It comes just days after a man died when a boat deflated in the Channel on Sunday, and it brings the number of people who have died while attempting the journey so far this year to 50.
Refugee charities have said deaths have become “appallingly regular” and they should not be normalised or accepted.
A group of people thought to be migrants are brought in to Dover, Kent, from a Border Force vessel following a small boat incident in the Channel (Gareth Fuller/PA)
A number of people wearing life jackets were brought ashore in Dover, Kent, by Border Force early on Wednesday, as crossings continued amid fair and smooth conditions at sea. No crossings took place on Monday or Tuesday.
As of Sunday, 29,867 people had made the journey from France this year, according to provisional Home Office figures.
This is 12% higher than at the same point in 2023 (26,605) and 22% lower than in 2022 (38,435).
Witnesses told PA two Border Force vessels arrived on Wednesday morning carrying up to around 100 people between them.
More boats are continuing to arrive, indicating the total figure is likely to have surpassed 30,000.
The number of arrivals recorded will be confirmed in Government figures being published on Thursday.
A Home Office spokesman said: “We all want to end dangerous small boat crossings, which threaten lives and undermine our border security.
“The people-smuggling gangs do not care if the vulnerable people they exploit live or die, as long as they pay. We will stop at nothing to dismantle their business models and bring them to justice.”