One migrant has died after a dinghy "deflated" in the Channel, plunging dozens of people into the water.
A Coastguard helicopter has been scrambled, along with lifeboat crews and Border Force personnel.
Kent Police said a woman died in the tragedy.
A source told the Daily Express the dinghy deflated as it reached UK waters.
Two seperate sources have claimed a migrant has died, prompting renewed fears over the callous tactics used by the people smugglers.
The RNLI have confirmed their involvement in "incidents in the Channel" on Tuesday afternoon.
An RNLI spokesperson said: "RNLI lifeboats have been tasked by HM Coastguard to incidents in the Channel today."
Two coastguard vans and ambulances are waiting to receive migrants at the Port of Dover.
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