Missing aristocrat Constance Marten and her partner Mark Gordon have been  taken into police custody after being found in Brighton amid a huge search to find their baby.

Officers were scouring a large area between Brighton and Newhaven to try to find the infant, who has not had any medical attention since birth in early January.

The Metropolitan Police said the pair were located and arrested by officers from Sussex Police in Stanmer Villas, Brighton on Monday night after a member of the public reported seeing them shortly before 9.30pm.

Marten, 35, and Gordon, 48, have been travelling around the UK by taxi since their car was found burning on the M61 in Bolton, Greater Manchester, on January 5.

Authorities previously believed the couple had been sleeping rough in a blue tent, and had avoided being traced by the police by moving around frequently and keeping their faces covered in CCTV images.

The couple travelled from Bolton to Liverpool, then to Harwich in Essex, then to east London and then to Newhaven in Sussex, where they were seen near the ferry port on January 8.

Constance Marten missing
Mark Gordon (GMP/PA)

Miss Marten, who is from a wealthy aristocratic family, was a promising drama student when she first met Mr Gordon in 2016.

Since then the couple have led an isolated life, and in September, when Miss Marten was well into her pregnancy, began moving around rental flats.

Gordon served 20 years in prison in the US for rape and battery committed when he was 14.

It is unknown if their baby was full-term or has any health issues.

In an appeal a week ago, Shereen Nimmo, director of midwifery for Barts Health NHS Trust, urged the couple to bring the baby in for checks.

She said: “You’re putting your baby at risk by not accessing medical care, so it’s really important that you come and see a midwife, doctor or another healthcare professional as soon as possible.

“Babies need a safe, warm environment and all new mums are given information about safe sleeping for their baby to prevent sudden infant death syndrome.

“Please do the right thing for your baby and go to your nearest healthcare facility so my caring colleagues can take care of you and your baby. All we want to do is help you.”

At the time, Detective Superintendent Lewis Basford said around 50 officers were working on the case at any one time and more than 630 hours of CCTV had been viewed.

He said there had been more than 350 calls to police from the public with information following previous appeals.

A £10,000 reward had been on offer for information that led to them being found safe.

Anyone who may be able to assist in the search for the couple’s baby is urged to contact 999.