Constance Marten and Mark Gordon arrested on suspicion of gross negligence manslaughter

Constance Marten and Mark Gordon have been further arrested on suspicion of gross negligence manslaughter, police searching for the couple’s newborn baby have said.

The 35-year-old aristocrat and her 48-year-old partner, Mr Gordon, were found by Sussex Police in Brighton on Monday night, following a vast seven-week search sparked by the discovery of their burnt-out car at the side of the M61 near Bolton.

The couple were initially arrested on suspicion of child neglect, but the baby – who is thought not to have been checked over by medics since it was born – was not seen with them.

A vast search for the child is under way, and detectives warned that the risk to the infant’s welfare was “as high as it’s been in the investigation” as they searched the Sussex undergrowth on Tuesday.

The couple have also now been arrested on suspicion of gross negligence manslaughter, senior investigating officer Detective Superintendent Lewis Basford announced on Tuesday evening.

DSI Basford said that police had to consider the possibility that the child had “come to harm”, given that the pair had now been in police custody for a “significant period of time”.

“We have had a significant period of time in custody facility with both Constance and Mark,” he said. “At this time we have not furthered that information, which has now obviously led to the position where we feel that the risk is getting so great that we now have to consider the possibility that the baby has come to harm.”

The couple, who are thought to have travelled hundreds of miles across the UK since abandoning their car near Bolton on 5 January, were detained after a 999 call by a member of the public who had seen media reports about the pair.

Since Marten and Gordon were arrested, more than 200 police officers have been engaged in the search for the two-month-old baby, using sticks to wade through bushes in woodland near Stanmer Villas and Golf Drive.

More follows