Police searching for Constance Marten and Mark Gordon’s missing baby say they must now consider that the baby has come to “serious harm” as the search continues in Brighton.

Detective Superintendent Lewis Basford from the Metropolitan Police gave an update in Stanmer Villas, on the past 24 hours of searching.

Det Supt Basford said: “This is a hugely difficult and painstaking search operation, covering a vast area of some 90 square miles.

“We’re using every resource we have at our disposal to find the baby.”

The search has continued today with voluntary search and rescue teams assisting police searching in parkland on the edge of Brighton.

Searches are also taking place in Newhaven and in other parts of the South Downs.

The couple remain in custody and investigators have applied for a 36-hour extension to hold them for further questioning.

Det Supt Basford urged the public to remain vigilant and continue providing information to the investigation team.

He was joined by Chief Superintendent James Collis from Sussex Police at around 2.30pm today.

Chief Supt Collis said: “Hundreds of officers from Sussex and the Metropolitan Police have been searching tirelessly overnight and that search is continuing.”

He also thanked the local community for its patience and understanding.

There will be an increased police presence in place for “some time” as the search continues.

Police are using a range of resources, including highly trained and specialist officers.

The forces continue to use drones, thermal imaging technology and the National Police Air Service (NPAS) helicopter to assist them in their search.

Det Supt Basford added: “Members of the public can help us by remaining vigilant and reporting any suspicious behaviour and items they have seen between January 8 [when the couple were first seen in Sussex] and Monday, February 27 [the date of the couple’s arrest].

“Please do not hesitate to report any potential sightings, no matter how insignificant it may seem to you.”

Anyone with any information is urged to call the Metropolitan Police on 02083453865 or 999 in an emergency.