Migrants desperate to reach England made at least 1,500 attempts to enter the Eurotunnel terminal overnight in the French port town of Calais, a police source told AFP Wednesday, adding that one man was found dead.
"Our team found a corpse this morning and the firefighters have confirmed the death of this person," added a Eurotunnel spokesman.
The migrant, a man of Sudanese origin believed to be aged between 25 and 30, was hit by a truck that was leaving a cross-Channel ferry, the police source said.
The overnight attempts at storming the Eurotunnel terminal after some 2,000 bids to enter the site were recorded the night before, in what was described as the "biggest incursion effort in the past month and a half".
British Prime Minister David Cameron on Wednesday expressed concern over the situation and said Home Secretary Theresa May would chair a meeting of the government's Cobra emergency committee to discuss the issue.
"This is very concerning," he told reporters during a visit to Singapore, adding that "we are working very closely" with French authorities to address the situation.
For several weeks, there have been many attempts by migrants to enter the Eurotunnel premises, with the numbers of people trying growing significantly in recent days.
"Everything happened overnight, and at 6:00 am (0400 GMT), the police still had quite a lot of work to do," said the police source of the last attempts, adding that "between 500 and 1,000 migrants" were still around the tunnel site.
The latest fatality brings the number of migrants who died near the Channel Tunnel terminal site to nine since June.
Security at the Calais port was stepped up in mid-June, driving migrants who previously tried to stow away on trucks that take ferries across the Channel to try their luck smuggling through the undersea tunnel.
According to the last official count in early July, around 3,000 migrants, mainly from Ethiopia, Eritrea, Sudan and Afghanistan, were camped out in Calais.