A couple who disappeared in England with their newborn baby have been found and arrested, but the child remains missing, said police. Constance Marten, 35, and her partner Mark Gordon, 48, a convicted sex offender, were located in Brighton almost two months after they were last seen. Hundreds of police have been involved in the search for the baby, who has been without medical attention since birth in January. Officers from Sussex Police arrested the couple in Stanmer Villas, Brighton on Monday night, following a tip-off from a member of the public. They remain in custody and are being questioned, police told the BBC. With bad weather forecast, Det Ch Insp Lewis Basford said people in the search area should look for signs of the baby and check sheds and outhouses. “We've seen the change in the weather forecast since January 5. My concern, as always, has been the baby being exposed to the elements,” he said. Ms Marten and Mr Gordon have been travelling around the <a href="https://www.thenationalnews.com/uk/" target="_blank">UK</a> by taxi since their car was found burning on the M61 in Bolton, Greater Manchester, on January 5. Authorities believed they were 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, east <a href="https://www.thenationalnews.com/tags/london/" target="_blank">London</a> and Newhaven in Sussex, where they were seen near the ferry port on January 8. Ms 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 Ms Marten was well into her pregnancy, began moving around rental flats. Mr Gordon served 20 years in prison in the <a href="https://www.thenationalnews.com/world/us-news/" target="_blank">US</a> 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 <a href="https://www.thenationalnews.com/tags/nhs/" target="_blank">NHS</a> Trust, urged the couple to bring the baby in for checks. “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,” she said. “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.” Anyone who may be able to assist in the search for the couple's baby is urged to contact 999.