Migrants have tried to cross the Channel to the UK amid thick fog over the Kent coast.
Border Force teams were seen earlier with a group of people thought to have attempted the crossing, and officials were spotted towing a rowing boat filled with oars into harbour at Dover.
The small blue and white vessel was paddled through the port by officials.
The Home Office said four boats had been intercepted carrying a total of 45 people.
It is thought the rowing boat was intercepted in the Channel in one of the earlier incidents, which took place at 07:00 BST, 08:20 BST and 08:20 BST, and was carrying a group of men.