A spokesperson for the French Maritime Prefecture said its rescuers investigate every call that they receive and that an inquiry was underway into the calls received that night.

“Sometimes we receive hundreds of calls in a night, each call is dealt with, and we have to work out which boat they are referring to,” said Veronique Magnin.

Callers sometimes express a preference to be rescued by the British, she said. However, this would not change the legal obligation for France to act.

The British coastguard declined to comment on Utopia 56’s legal complaint. It said that on November 24, it had received more than 90 alerts from the Channel area including 999 emergency calls.

“Every call was answered, assessed and acted upon, including the deployment of search and rescue resources where appropriate,” it said.

The tragedy worsened already deeply strained diplomatic tensions between London and Paris after a raft of disagreements from Brexit to fishing.

Trading blame, Britain asked France to do more to prevent migrants from leaving their shores, while French president Emmanuel Macron accused Boris Johnson of being “not serious” in seeking a solution to preventing such crossings.

According to the investigation, the migrants left in an inflatable boat from Loon-Plage in northern France at night.

After their boat capsized only two men, an Iraqi Kurd and a Sudanese national, were rescued safely.

According to the Iraqi survivor, there had been a total of 33 people aboard.

The legal complaint came as a 16-year old Sudanese migrant died after he was hit by a lorry near Calais. According to the prosecutor’s office at Boulogne-sur-Mer, the victim had attempted to board the vehicle at a logistics zone early on Monday morning.

“He managed to climb between the cabin and the trailer. And just as the driver started up again, the migrant fell,” it said.

The Eastern European driver was slightly injured after a group of 40 migrants threw stones at his vehicle. An investigation has been launched into manslaughter.

Meanwhile, prosecutors opened a separate probe into “blows unintentionally leading to death” after a Portuguese truck driver was found dead, apparently after a fight with a group of migrants seeking to board his lorry at Beuvrequen near Calais.

The man had an injury under his eyebrow, according to the local prosecutor. However, the 48-year-old, who had health problems, did not die from the blows but from “heart failure”.

“There may be no link between the blow and the death,” said the prosecutor.

According to a source close to the inquiry, the driver had rung the police to alert them to the presence of migrants in his trailer, leading to a fight. He then sought refuge in a neighbouring truck only to collapse.