Constance Marten and Mark Gordon were found by Sussex Police after being spotted by a member of the public in Stanmer Villas, Brighton, shortly after 9.30pm on Monday, February 27.
The couple and their baby had been missing since their car was found burning on the M61 in Bolton, Greater Manchester, on January 5.
Police say the baby they were with is still missing and an urgent search operation is taking place in the area.
A police spokesperson said: “Shortly before 9.30pm on Monday, 27 February, a member of the public reported a sighting of Constance Marten and Mark Gordon in Stanmer Villas, Brighton.
“Officers from Sussex Police attended the location and the pair were arrested. They remain in custody. The baby is still missing and an urgent search operation is taking place in the area.
“Anyone with information that could assist the search is asked to call 999.”
Eddie Mitchell was at the scene and here are the pictures…..
1. Baby hunt Brighton 28-2-23 - possibly living in caravan pictured Constance Marten and Mark Gordon have been sleeping rough and travelling around the UK by taxi for six weeks
Police are still urgently searching for a missing baby after its aristocrat mother and her partner were found and arrested in Brighton. Photo: Eddie Mitchell
2. Baby hunt Brighton 28-2-23 - possibly living in caravan pictured Constance Marten and Mark Gordon have been sleeping rough and travelling around the UK by taxi for six weeks
Police are still urgently searching for a missing baby after its aristocrat mother and her partner were found and arrested in Brighton. Photo: Eddie Mitchell
3. Baby hunt Brighton 28-2-23 - possibly living in caravan pictured Constance Marten and Mark Gordon have been sleeping rough and travelling around the UK by taxi for six weeks
Police are still urgently searching for a missing baby after its aristocrat mother and her partner were found and arrested in Brighton. Photo: Eddie Mitchell
4. Baby hunt Brighton 28-2-23 - possibly living in caravan pictured Constance Marten and Mark Gordon have been sleeping rough and travelling around the UK by taxi for six weeks
Police are still urgently searching for a missing baby after its aristocrat mother and her partner were found and arrested in Brighton. Photo: Eddie Mitchell