A CASH reward worth £10,000 has been offered in the hunt for missing aristocrat Constance Marten, who was spotted in Harwich and Colchester earlier this month

The 35-year-old, who is from a wealthy family with connections to the royals, has lived an isolated life with her boyfriend Mark Gordon, who is a convicted sex offender,  since they met in 2016.

The couple and their newborn went missing in early January, and during that time, Marten has been seen in Colchester, prompting police to search every hotel in the city.

Marten is also believed to have been spotted in Harwich at 9am on Monday, January 9, before she was seen in Colchester one hour later.

The family has been sleeping rough in freezing temperatures as they try to avoid being found, and detectives believe Marten gave birth to her son in the back of a car, which was then found burnt out on the M56 in Greater Manchester.

On Tuesday, the Metropolitan Police revealed details of the cash reward which will be offered to anyone who can offer any information which could lead to them being found.

Thurrock Gazette: Mark Gordon and Constance Marten walking through Flower and Dean Walk near Brick Lane, east LondonMark Gordon and Constance Marten walking through Flower and Dean Walk near Brick Lane, east London (Image: Metropolitan Police/PA)

Detective superintendent Lewis Basford, who is leading the investigation, said: “We continue to be extremely concerned about the health and wellbeing of the newborn baby, which has had no medical care and has been on the move, and possibly exposed to sub-zero temperatures, for almost a month now.

“We’re also concerned for the welfare of Constance and Mark, because our inquiries suggest that they were constantly moving and awake for at least a few days – which must be especially draining on someone who had recently given birth with no medical attention.

Thurrock Gazette: Mark Gordon and Constance Marten in Allison Road, Haringey, north LondonMark Gordon and Constance Marten in Allison Road, Haringey, north London (Image: Met Police/PA)

“Finding the baby is our top priority and we are now offering a £10,000 reward to anyone who provides information which leads to them being found.

"Maybe you have been reluctant to come forward before, for whatever reason, with key information to help us find the family.

Marten is the daughter of Napier Martin, an aristocrat who was a page to Queen Elizabeth II.

Forty-eight year old Gordon, who has a rape conviction, was born in Birmingham and lived in Florida, then returned to the UK after serving a 20-year jail term.