Footage of suspected illegal migrant arrests in Portsmouth
The arrest of 28 suspected illegal immigrants discovered hiding in a lorry in Portsmouth was captured on mobile phone footage obtained by the BBC.
Ten Sudanese, seven Ethiopian and 11 Eritrean nationals were found by police in the back of an HGV in May.
One person remains in hospital and a minor is in the care of social services, the Home Office.
The owner of a nearby lorry park who saw the arrests told the BBC the migrants were brought to his business to use facilities after they had been freed from the lorry.
The Road Haulage Association said "minor ports" like Portsmouth were seen as a weakness in the UK's border and has called for better security.
A Home Office spokesperson said: "Border Force keeps the situation at the border under constant review and maintains an agile, flexible and intelligence-led approach at all times.
"We also work proactively with European law enforcement, including partners in France, Belgium and Holland, to target the organised crime networks behind people trafficking and illegal migration."
According to Brittany Ferries, security at ports is "consistently being tightened to prevent clandestine passengers from gaining access to the United Kingdom".
"Even though, thus far, western Channel and Spanish ports have been less impacted than those further east, we are far from complacent," it said.
Hampshire Constabulary said it would not comment on specific incidents.