Two German men are still being questioned by investigators after sparking a security alert which temporarily shut one of the main gateways to Britain.
The pair, aged 36 and 43, were believed to be en route to a military show when they were stopped in vehicles containing military collectors' items at the Port of Dover in Kent, sources said.
One was in a lorry and the other in a van when they were detained by UK Border Agency (UKBA) officials at the port's Eastern Docks after arriving from France yesterday evening.
The items they had included weapons, prompting authorities to throw a 200m safety cordon around the port and hold ferries approaching Dover in the English Channel.
Ministry of Defence bomb disposal experts were drafted in to assess the weapons, Kent Police said.
After being declared safe, the docks were reopened nearly two hours later but the alert caused heavy congestion on roads leading to the port, including the A2 and A20.
A UKBA spokesman said today: "Following an incident at the Dover Eastern Docks yesterday which led to the discovery of a number of suspicious items, two German men, aged 36 and 43, have been arrested on suspicion of customs offences.
"They are currently in custody and are being questioned by UK Border Agency investigators."