Activists on the No Borders / Calais Migrant Solidarity Facebook page have been discussing how Tuesday’s bombing in Brussels was a “good thing,” as the chaos it caused will have enabled illegal immigrants to cross into the UK. One activist urged others to exploit the situation, saying: “Tell your friends in the jungle.”

Their prediction has proved correct as, hours after the Home Office announced extra security measures at Channel cross-border crossings, a lorry-load of illegal immigrants was discovered in Kent.

The discussion was prompted by Chiara Lauvergnac, a self-described “freelance troublemaker”, who wrote: “Eurostar to Brussels suspended, Lille airport is taking some of the planes due to land in Brussel[s] airport. It could mean some chaos and good chance some people will go to UK! Sorry there is a good side to everything,” and posted the comment to the Calais Migrant Solidarity Facebook page.

Gemma Rourke questioned “Sorry a good side to people being killed this morning?” to which fellow activist ‘Rojo Red’ replied: “Whether it’s a “good side” to people being killed is really irrelevant to me.”

He added: “Brussels Eurostar traffic suspended, thus a real possibility of increased traffic at Calais Eurostar. Tell your friends in the Jungle!”

Lauvergnac has also used her personal Facebook page to link to two articles suggesting that yesterday’s Islamic terrorist atrocity was a “false flag” operation fabricated by Western leaders, designed to increase support among the public for higher governmental security measures. Another post is of an image which reads: “My heart truly bleeds for what happened in Belgium… But Palestinians have faced attacks for almost 70 years from Israeli terrorists and the world is still silent.”

Aware of the potential threat, the Home Office yesterday announced that it had tightened border security in response to the Brussels attacks on Tuesday, insisting that all heavy goods vehicles were being checked at Dunkirk, Calais and Coquilles. Dogs were being used to sniff out stowaways, they said, as well as carbon dioxide probes to detect breathing and x-ray scanners to search trucks.

Yet hours later, 26 migrants were found in the back of a lorry in Canterbury, Kent, including a woman and a boy of unknown nationality. The truck, carrying £25,000 worth of goods that would have to be written off, belonged to fruit and veg company Gomez.

Jim Parmenter, managing director of the family-run British firm said this was the third time his lorry had been targeted by immigrants in a month, forcing him to write off a total £80,000 worth of produce.

“Our staff heard banging with large metal objects on the doors from inside the truck. Our politicians are telling us things are getting better but they’re not — they’re getting worse,” he said.

Despite assurances from the Home Office that all vehicles are undergoing checks following the Brussels attack, a union official has said that, in reality, fewer than half of the lorries are checked.

Lucy Moreton, general secretary of the Immigration Services Union told the Times that it was impractical to carry out full checks: “We cannot check all freight coming to the UK,” she said. “There is too much coming through. Less than half of it is checked.”

Consequently lorries are only checked if there is specific intelligence implicating a vehicle, she said, but even then, the checks don’t always find hidden people.

Keith Vaz, chairman of the Commons home affairs select committee, said: “These revelations are astonishing. At a time when we should have heightened border security, to discover so many people coming in illegally is a cause for deep concern. The worry is that those who are not coming to work but are coming to cause security problems for our country may slip in this way.”