Migrants successfully landed on a Kent beach for the first time in almost three years after avoiding detection as they crossed the Channel, a Home Office investigation has concluded.

Five people were detained on September 6 after they were found on a beach near Deal, Kent.

Home Office insiders confirmed at the time that an investigation had been launched – but stopped short of declaring an alarming security blunder.

But they have now concluded the migrants did reach the UK undetected, making it the first uncontrolled landing since 2022.

Sources described it as “an isolated and rare incident”, adding “there are significant arrangements and technology in place to prevent uncontrolled landings from taking place.”

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.

Chaos has erupted in the Channel over recent weeks, with smugglers launching boats with an average of 80 people destined for the UK.

Witnesses said some of the 13 boats detected on Friday – when 1,072 people arrived – crossed into ferry and shipping lanes, triggering fears of a disaster.

The French Coast Guard even called passenger ferries in UK waters “asking them to keep clear of oncoming migrant dinghies”, the Daily Express understands.

In one alarming incident a Border Force vessel went to pick up dozens of migrants as a French rescue ship tried to alert the captain of the Côte Des Dunes about their presence.

But another group of asylum seekers were discovered nearby, witnesses said, meaning the Border Force boat had to be diverted.

The lifeboat then raced in and stayed with the dinghy to prevent an extraordinary catastrophe in one of the busiest shipping lanes in the World.

Migrant boats often lack the power to cut through the water, meaning they can veer off course at any moment.

And boats have been seen collapsing as they reach British waters, because they are crammed so full.