A young mother who abandoned her newborn boy on a doorstep has begged for forgiveness in emotional anonymous letters sent to the couple who found the infant.

She insisting that she loved her child - but wanted him to have a better life.

The 6lb 8oz baby was found at 1.50am on March 18 on the doorstep of a bungalow in Fen Lane, Sawtry, Cambridgeshire. He was taken to Hinchingbrooke Hospital in Huntingdon where nurses named him Patrick Brian after St Patrick's Day and Brian, the paramedic who brought him in.

The infant, who is white, and has a small amount of fair hair, is said to be healthy is now in the care of Cambridgeshire social services, being looked after by foster carers.

He was found by retired civil servant Lance Ayres, 70, and his wife Beryl, 68. They had been woken after hearing the baby cry and found him wrapped in a pink sheet and a grey chequered shirt.

On Friday the couple received a package containing four letters.

The letters were in a white self-seal envelope and had a hand-written address to Mr and Mrs Ayres, Fen Lane, Sawtry or the Police in black ink. It did not have a stamp and bore no postmark.

Inside were four separate letters this time written in blue ink: one to Mr and Mrs Ayres, one to Mr Brian Brooker, the paramedic who first cared for Patrick, one was addressed 'to whom it may concern' and the fourth was a letter to Patrick.

Police have released the text of the letter written to Mr Brooker and details from the other letters.

In her letter to Mr Brooker - a copy of which can be seen by clicking on the photo - the mum says: "I am OK just a bit tired and need to be on my own.

"I am not going to come forward because I know how much trouble I am in and how much people hate me now.

"Please tell Mr and Mrs Ayres not to hate me. I am not a bad person. I had Patrick on Saturday night and hid him until my parents were asleep.

"I cannot tell anyone because no one understands. Please forgive me."

PC Nicola Hood, one of the officers leading the investigation, said: "If the letters are genuine, and there is no reason to think that they are not, then it does appear that the mother may be fairly young and possibly living at home with her parents. It is also likely that she is local to the Sawtry area."

The letter to Mr and Mrs Ayres thanks them for taking care of Patrick and explains that she had to leave him because she is on her own and wanted him to be in a loving family who could give him more than she ever could.

In the letter to Patrick she says she will love him forever, but felt that her actions were for the best and she hopes one day he will understand.

In the final letter - addressed to whom it may concern - she states she does not wish to be found and that the birth was fine and again asks for forgiveness for her actions.

She also says that she returned to Mr and Mrs Ayres' home after abandoning her baby but went away again because there were so many people around.

PC Hood said: "I'd ask everyone to please look carefully at the hand-writing and anyone who recognises it should come forward.

"If anyone has any idea who she is, or where she is they should contact police, in confidence if necessary."

"Our aim remains to find her and to offer her the support she needs at this time, both medical and emotional. Whatever her reasons for leaving Patrick and whether or not she wants to be reunited with him is not the key issue here - it is her welfare."

She also urged Patrick's mother to come forward and talk to police.

"No one hates you and none of us know your circumstances," she said. "It is obvious from your letters that you care about Patrick and no one is judging you for what happened."

"But please be reassured that there is help and support available to you which you can only get if you come forward. You can ring me personally - I am waiting for your call."

Officers are also trying to trace a woman who phoned their main switchboard last week saying she had information about the baby's mother - but hung up before giving any details. The woman phoned at 10.20pm on Thursday.

PC Hood said: "We are appealing for this caller to get in touch with us again. We do not know if she was Patrick's mum or not but we do feel that she had something really important to tell us and we would ask her to please call back."

Officers have also release this photograph of the shirt that Patrick was found wrapped in to keep him warm.

The blue and grey chequered shirt is a child's size, probably for no older than a two-year-old. Patrick was also wrapped in a pink sheet when he was discovered.

PC Hood said: "I'd also ask everyone to check their airing cupboards to see if they have a sheet missing. Perhaps you had one taken from a washing line and never reported it? "

Another clue is the noise of a crying baby and female voices heard in Sawtry between Saturday night and the early hours of Sunday morning. They were heard in the Ermine Way area of the village.

The letters and phone call came after officers distributed posters in the Sawtry in an effort to try to jog people's memory or conscience.

Anyone with information can contact police, in confidence on 01480 456111.

Another baby abandoned

Meanwhile police are trying to trace the mother of another baby which was abandoned in Buckinghamshire

The 8lb newborn baby boy was found in Buckingham on Friday night in a waste bin and was today "doing very well" in hospital where hospital staff have called him James after the man who found him.

Jim Darcy was walking in Bourton Meadow Park to a pub for a late-night drink when he heard the baby's screams. The noises him led him to a bin bordering a children's playground.

Mr Darcy said: "I looked in the bin and was surprised to see a baby. My natural instinct was to take the baby out and keep it warm. I wrapped him in my jumper and walked back towards my house."

He went to neighbours and alerted police and paramedics.The baby was currently being cared for at Milton Keynes General Hospital and is said to be in a stable condition.

He added: "He's a lovely baby and the police have said he's doing very well. We want the best for him and his mother and we would appeal for anyone to come forward who knows who the mother is in order that she can receive the help she may need."

Police believe James's mother may have given birth close to where her baby was discovered and fear she may have suffered difficulties in the birth.

Thames Valley Police used the force's helicopter in a major search of the surrounding area but they were unable to trace the mother.

Superintendent Dave McBirny, who is leading the investigation, said: "Our priority at this time is to trace the mother. While the baby is fit and well in hospital there are indications this may have been a difficult birth and the mother is likely to be in need of medical attention."

He appealed for anyone who may have been in the area of the park between 6pm and 10pm on Friday night to contact police.

Anyone who can help is asked to call 01296 396039.