Police have seized a pair of pink child's earmuffs as the search for Constance Marten's missing baby continues in the city. 

The earmuffs were found in Roedale Valley Allotments in Hollingbury, Brighton. 

Sussex Police and the Metropolitan Police have been searching for the baby in Hollingbury after missing aristocrat Constance Marten and her boyfriend Mark Gordon were found last night. 

The pair were arrested on suspicion of child neglect and remain in police custody at this time. 

A spokesman for the Met Police said: "The baby is still missing and an urgent search operation is taking place in the area."

The baby has not had any medical attention since it was born in early January.

The couple have been avoiding police since the infant was born in early January, moving around the country, paying for everything in cash and covering their faces when on CCTV.

The Argus: The pink earmuffs were seized by policeThe pink earmuffs were seized by police (Image: Andrew Gardner/ The Argus)

They were finally arrested at around 9.30pm on Monday on suspicion of child neglect by officers from Sussex Police.

The couple were held in Stanmer Villas after a tip-off from a member of the public, but the baby was not with them.

The Argus: These pink baby's earmuffs were seized by police These pink baby's earmuffs were seized by police (Image: Andrew Gardner/ The Argus)

Senior investigating officer Detective Superintendent Lewis Basford told BBC Breakfast that officers from the Metropolitan and Sussex police forces are searching a huge area of land to try to find the infant.