A Sudanese teenager who disappeared at sea has been found dead on a beach near Calais, a French minister has said.

Marlene Schiappa, who is in charge of citizenship in France’s government, said the 16-year-old was found on the beach of Sangatte on Wednesday morning.

The rising number of refugees and migrants making the perilous crossing of the Channel has been a focus of the UK government of late.

The home secretary, Priti Patel, who has pledged to make the route “unviable”, said the death was “an upsetting and tragic loss of a young life”.

She added: “This horrendous incident serves as a brutal reminder of the abhorrent criminal gangs and people smugglers who exploit vulnerable people. Working together, we are determined to stop them.”

Shiappa also said the death highlighted the need to tackle the smugglers. “Immense sadness: a 16-year-old Sudanese migrant who disappeared in the sea last night was found dead in the beach in Sangatte this morning,” she tweeted.

Meanwhile in Dover, children were among dozens of refugees and migrants who arrived on Wednesday morning. More than 50 people were taken into the Kent port on Wednesday morning onboard a lifeboat and a Border Force vessel.

There have been urgent discussions on where to house migrant children who travel to the UK without family. It emerged earlier in the week that any new, unaccompanied asylum-seeking children would be left with Border Force, after Kent county council announced it had reached capacity.

Bella Sankey, the director of Detention Action, a campaign group, said: “It is devastating to learn that a child has now died in the Channel while trying to seek safety in the UK. This is a horrifying but wholly expected death.

“We have repeatedly warned Priti Patel it was only a matter of time before her toxic policy to deny safe and legal routes to the UK would cost lives. This death lies firmly at her door. She should consider her position.”