The "English mafia" is involved in smuggling migrants out of France to the UK, a mayor has alleged.
It has been claimed that UK-registered cars, driven by British drivers, are being used to traffic people from a camp on the outskirts of Dunkirk to locations where they can try to stow away on lorries.
The mayor of nearby Teteghem, Franck Dhersin, told the BBC that Brits who complained about migrants did not realise "the cars are English and the owners are English", and that cars - driven by what he called English mafia - were often spotted there.
He added that the traffickers were violent and simply wanted to make money.
Mr Dhersin said they had been operating in the area for a number of years, but had now become more organised.
He had insisted on making visits to the campsite in Teteghem, until he was shown a gun and a reporter he was with was threatened with rape on Tuesday.
The previous day Ukip MEP claimed a migrant threatened him with a handgun as he visited a camp on the outskirts of Dunkirk.
Mike Hookem, the party's defence spokesman, said his group were invited to access a woodland site near the seaside town by migrants who were "milling around".
But he said the "situation immediately turned nasty" after another man at the camp appeared holding a handgun and stopped them from entering.
He said the incident left a woman in his group of five people "very frightened".
The MEP for Yorkshire and North Lincolnshire said he wanted to visit the camp to understand more about the migrants and their reasons for wanting to reach the UK.
A Home Office spokesperson said: "We are working closely with the French authorities to deal with the situation in northern France.
"We are increasing joint intelligence work to target the organised crime gangs behind people smuggling and the NCA, along with Border Force and Immigration Enforcement, continue to work closely with French (Ocriest) counterparts.
"We must also treat the causes of this problem, not just deal with its consequences. The UK is playing a leading role in pushing for action through the EU and the UN to tackle the causes of illegal immigration and the organised trafficking gangs behind it that exploit migrants at each stage of their journey."