Four people were confirmed dead after a small boat loaded with migrants heading for British shores from France capsized in the waters of the English Channel early on Wednesday, the British government said.

"At 0305 (GMT) today, authorities were alerted to an incident in the Channel concerning a migrant small boat in distress," a government spokesperson said in a statement.

"After a coordinated search and rescue operation led by HM Coastguard, it is with regret that there have been four confirmed deaths as a result of this incident, investigations are ongoing and we will provide further information in due course."

An investigation was underway, the spokesperson said.

LBC radio station reported that 43 people had been rescued.

(Cover: A lifeboat returns to the Port of Dover amid a rescue operation of a missing migrant boat, in Dover, Britain, December 14, 2022. /Reuters)