Dutch prosecutors have confirmed that a small boat carrying 38 migrants found adrift off the Netherlands launched from Dutch territory, the first such departure from the Netherlands.

The rubber boat was spotted near Breskens and Cadzand, on the Zeeland coast, on Saturday 31 October after its engine failed. It was towed into Cadzand harbour by Dutch coastguard and military police. On board were 36 Afghan men, including six boys under 18, and two Sudanese men arrested on suspicion of people smuggling. Their detention has been extended by 14 days.

The Dutch prosecution service, the Openbaar Ministerie, confirmed on 5 November that the passengers had entered the water from Dutch territory, without disclosing the exact departure point. Cadzand is about 100 miles from Dover, well over three times the Calais crossing.

Nigel Farage called for the Royal Navy to be deployed in the Channel, writing on Facebook on 6 November: "Illegal migrants are now being smuggled from THE NETHERLANDS... The only way to stop this is to put the Royal Navy in the Channel."

Smugglers adapting to enforcement

Dover MP Mike Tapp said smugglers were adapting as launch sites were disrupted. "As launch disruptions grow, the criminal gangs will adapt and a part of that will be finding new launch locations and methods," he said. Dutch deputy prime minister Bart van den Brink called the incident "highly disturbing", saying it was the first time such a launch had been seen in the Netherlands.

Red Cross volunteer Bastiaan van Blokland, who attended the scene, said conditions were dire, with 38 people, legs dangling, in cold water and without an engine. The Home Office said joint work had prevented more than 50,000 crossing attempts, and that 22,128 people crossed between 1 January and 31 October.