A 27-year-old Sudanese man has been arrested on suspicion of endangering life after four people died trying to board a small boat to cross the Channel on Thursday, the National Crime Agency (NCA) has said.

Two men and two women, whose identities have not been released, died while trying to board a water taxi off the coast of Saint Etienne au Mont, near Calais.

Thirty-eight people were returned to the French shore but 74 “sailed on to the UK”, the NCA said, and investigators are in the process of interviewing those that made the journey.

The suspect was arrested at Manston processing centre in Kent – which processes people that arrive by small boats – and remains in police custody.

French prosecutors are also investigating the circumstances that led to the launch of the boat, and the NCA said it is “assisting French police partners with those enquires”.

NCA deputy director Craig Turner said: “Working with colleagues at home and abroad, we are determined to do all we can to identify and bring to justice those responsible for these four tragic deaths.”

Migration minister Mike Tapp said: “Every death in the Channel is a tragedy.

“Our experienced law enforcement teams will continue working relentlessly with international partners to prevent these perilous journeys and bring those responsible to justice.”

He added that the Border Security Act, introduced at the end of last year, has given “officers stronger powers to act earlier and disrupt, intercept and take down the operations of criminal smuggling gangs who bring illegal migrants to our shores”.