Police attempting to track down a dangerous sex offender who absconded from an open prison three days ago have issued new pictures of him without a distinctive braided beard.

Paul Robson, described as a “particular danger to women and young children”, is serving a life sentence for attempted rape and indecent assault and was reported missing from HMP North Sea Camp near Boston at about 7am on Sunday, Lincolnshire Police said.

Officers have urged people not to approach the 56-year-old, who arrived at the open prison on January 21 this year, as he “can cause real harm to anyone he comes across”.

Police have said Robson has a dark donkey jacket with a large collar and blue on the shoulders in his possession.

In a statement, the force said: “We also believe that his facial hair might not look similar to the image we’ve previously circulated, and that it might not be tied and may be lighter in colour.”

During his fifth parole review in February last year, Robson was refused release but recommended for a move to the Category D open prison.

The Newcastle-born sex offender was jailed at Oxford Crown Court in 2000 after he entered a woman’s home through a cat flap before tying her up, putting a pillow case over her head, and brutally assaulting her while holding a knife to her throat.

He was handed a life sentence with a minimum term of nine years, but has spent an additional 11 years in prison.

Robson had only been released from prison three weeks before the attack and was on licence – with the sentencing judge describing him as a “menace to females”.

Providing an update on the search, Chief Superintendent Kate Anderson said: “It has now been three days since Paul Robson was last seen and we continue to appeal to members of the public for their help to find him.

“We are keeping an open mind as to his current whereabouts and we’re pursuing extensive lines of enquiry based on the information that the public have shared with us so far.

“We’re grateful to those who have already contacted us, and we would urge people to continue doing so.

“Any information, no matter how small, is useful in allowing us to build a bigger picture and it leads us closer to taking a dangerous man off our streets.

“We understand there may be concerns around personal safety, but we have allocated a number of resources to this investigation to aid in his swift arrest.

“Rest assured we are taking this seriously and advise that if you do see him, please contact us immediately and try not to approach him or apprehend him yourself.”

After Robson is caught, it is understood he would be returned to a closed prison and not be eligible for parole for at least a further two years.

The prisoner was previously described as a white male with a bald head, a long goatee beard and of a slim build.