In a clear sign they did not believe the suspects were linked to the drownings, their case is being handled by a separate prosecutor in Dunkirk.

The Lille prosecutor confirmed that seventeen men, seven women and three “young people who could be teenagers” (two boys and a girl) died when the inflatable boat lost air and took on water off the northern port of Calais on Wednesday.

It confirmed that the lives of two survivors who were recovered with advanced hypothermia were “on the face of it not in danger”.

Speaking to RTL radio on Thursday morning, Mr Darmanin said that the fifth suspect had been driving a car with German number plates and had “bought inflatable boats in Germany”. He said 1,500 suspected people smugglers had been arrested in France since the beginning of the year.

He said they “operate like mafia organisations”, using encryption to stop police tapping their phone conversations.

“The main responsibility for this situation lies with the smugglers,” Mr Darmanin said, describing them as “mafia-like organisations in Belgium, the Netherlands, Germany and Britain”, adding: “France and Britain have to work together. We can no longer be the only countries to be fighting these smugglers.”

In telephone talks, Boris Johnson and Emmanuel Macron agreed on the “urgency of stepping up joint efforts to prevent these deadly crossings” and that “it is vital to keep all options on the table” to break the business model of the smuggling gangs, according to Downing Street.

However, with pressure high on both sides of the Channel, the blame game continued.