A migrant died after a dinghy deflated in the middle of the English Channel, plunging dozens of people into the water. The woman was winched out of the water by a Coastguard helicopter and flown back to Dover.

But she was pronounced dead at the scene despite emergency crews administering CPR. Sources have told the Daily Express the migrant dinghy collapsed as it reached UK waters, triggering a huge emergency operation involving Border Force, the Coastguard and RNLI. They claimed the woman who lost her life was “crushed”.

The migrant vessel was being shadowed by the French at the time, this newspaper understands.

Witnesses also claimed the French did not intervene and waited for the British Border Force vessels and RNLI to arrive.

More than 500 people are believed to have attempted the crossing on Tuesday – just days after 1,097 were detected.

A government spokesperson said: “We can confirm that Border Force responded to reports of a migrant boat in distress in the Channel at 12.45pm. One passenger was found unresponsive and was given CPR. Sadly, we can now confirm that this individual has died.

“We are shocked and saddened by this tragic incident. Our immediate thoughts are with all of those who have been affected.

“This latest tragedy underlines the terrible dangers of small boat crossings, and we continue to do everything we can to prevent callous criminals exploiting vulnerable people.”

It comes as the Home Office launched a separate investigation into claims migrants successfully reached the Kent coast on Saturday.

French vessels generally escort the migrants’ dinghies once they are in the sea to the Channel median line before they are picked up by Border Force, RNLI or Coastguard boats to be brought back to Dover.

But the discovery of five men near Deal, Kent, has prompted fears that migrants successfully evaded Border Force and the French.

They have all been detained.

A Downing Street spokesman said on Tuesday: “The circumstance of their arrival is still being investigated, and there hasn’t been a conclusion to that investigation.

“I don’t want to get ahead of the investigation, but obviously the Home Office will keep their data updated, consistent with the results of their investigation.”

Asked why the investigation had not been made public, the spokesman replied: “Well, that’s because there’s an investigation, which we don’t have the results of and therefore can’t provide any commentary … once the investigation has concluded, we’ll provide that update.”

The French are under intense pressure to finally start intercepting migrant boats in the water.

This would make it far harder for people smugglers to launch so-called taxi boats.

And Home Office officials have drawn up a series of other proposals to stop migrant dinghies reaching UK waters.

One option under consideration could see British vessels blocking asylum seekers from crossing the median line.

Migrants would then be picked up and taken back to France, Bloomberg reports.

However, the proposal would need the backing of the French Government and securing such an agreement could prove tricky.

New Home Secretary Shabana Mahmood is also said to be considering the idea of constructing a barrier in the Channel and removing the need for the Coastguard to automatically rescue any small boat in its waters.

More than 30,000 migrants have crossed this year, with the number of arrivals surging at a record pace.

The UK is considering suspending visas from countries that do not “play ball” and agree migrant deportation deals, Ms Mahmood declared.

The new Home Secretary warned that countries must take back foreign criminals, failed asylum seekers and visa overstayers.

And Ms Mahmood vowed to do “whatever it takes” to stop small boat crossings, adding she will go “further and faster” than Yvette Cooper.

A staggering 1,097 asylum seekers crossed the Channel in 17 boats on Saturday – Ms Mahmood’s first day in office.