Shortly after midday today (January 9), an inflatable dinghy got into difficulty around 23 miles south of Beachy Head.
Rescue teams from HM Coastguard and the RNLI scrambled to return the boat, which had around 30 migrants on board, including children.
All of its occupants have now safely been returned to shore and taken into the care of the Home Office.
A spokesman for Sussex Police, which supported rescue teams, said: “This afternoon, Sussex Police supported Border Force staff in rescuing a number of people suspected of not having authority to enter the UK who had been in a vessel towed safely by the RNLI and into Sovereign Harbour in Eastbourne.
“Those detained are being taken into custody and care by Border Force.”
An eyewitness said the rescued suspected migrants were being given hot drinks and assessed by paramedics.