Police are on the search for a registered sex offender named Mark Gordon who spent 20 years in jail for rape and battery.

Authorities are also on a countrywide search for a woman by the name of Constance Martin as well as her newborn baby after the couple vanished on January 5.

They were seen on the M61 after their car broke down and caught on fire near Bolton.

Police say the couple has a substantial amount of cash on them, allowing the pair to live off the grid.

The Bolton News: PA - The couple is said to know how to avoid authorities, making their search much harderPA - The couple is said to know how to avoid authorities, making their search much harder (Image: PA/GMP)

It is also said the couple have no luggage with them after most of their belongings were burned in the car fire earlier this month.

Constance Martin, who is 35, comes from a wealthy aristocratic background but the couple has been understood to have largely lived in isolation since 2016.

The drama student cut off ties with her family and friends before moving around the country with Mark Gordon.

After they abandoned their car, they walked to Anchor Lane Bridge where they got a taxi to Liverpool before taking another to Harwich in Essex.

They were spotted around Colchester on Friday, January 6 and 7 before taking another taxi to East Ham station in Newham, London, where they were last seen.

Investigators say that the couple seems to know how to avoid police, making the search for them much harder.

It is also believed that they could be anywhere in the UK, with police asking the public to come forward if they have any information.

Around 200 officers are looking for the couple and their baby and over 200 hours of CCTV have been looked at by the police since they were last seen on January 7.

According to a criminal record viewed by ITV News, Gordon was convicted of kidnapping and sexual battery when he lived in Florida.

The 48-year-old served 20 years behind bars and was eventually deported back to the UK.

Marten, on the other hand, grew up in Crichel House in Dorset and was part of a family with close links to the Royal Family.

The Sunday Times said that her grandmother was a playmate to Princess Margeret while her father was a page to the late-Queen Elizabeth II.

Detective Superintendent Lewis Basford, who is heading the investigation, said: “It has now almost been two weeks since Mark and Constance’s car broke down on the M61 near Bolton and they have been on the move all that time with a newborn baby.

“As far as we are aware, neither Constance nor the baby have received medical attention since it was born. Our priority is to ensure the baby, and indeed both Constance and Mark, are safe and well.

“Once again, I appeal directly to you Constance and Mark. Please do the right thing for your baby and get in touch with us so that we know that you are all doing okay.”