A woman who went missing with her three-year-old son has insisted she had 'no other choice' to give him a 'semblance of a childhood with his mum'.

Ellie Yarrow-Sanders, 26, of Basildon, Essex, disappeared with Olly Sheridan six months ago and has insisted she will 'never let any harm come' to him.

Miss Yarrow-Sanders disappeared with Olly in July a few weeks before she was due to give evidence in a 'critical' family court hearing, according to lawyers.

Ellie Yarrow-Sanders, 26, disappeared six months ago with son Olly Sheridan (left, together) - and the boy's father Patrick Sheridan (right, with Olly) has begged them to come out of hiding

Miss Yarrow-Sanders denied causing her son 'emotional harm' in the letter (pictured above)

The note, in which she denied causing her son 'emotional harm', said: 'This letter is for you to understand why I've had to do what I've done.

'It's for you to show to the police and the court to explain myself. This is the only thing I could do for Olly to have any semblance of a childhood with his mum.

'I'm really sorry to leave you all but we have no other choice and I promise we will be OK! I will never let any harm come to Olly.'

The letter was first published online last year but has only just come to light as her estranged partner Patrick Sheridan, 45, renewed an appeal for information.

Earlier this week civil engineer Mr Sheridan said: 'I hope that Ellie sees sense and comes forward so that this can be sorted out and Olly can have a normal childhood, not living on the run.

Olly (left) who is at the centre of a family court dispute between his estranged parents, disappeared with Miss Yarrow-Sanders (pictured together, right) weeks before she was due to give evidence in a family court hearing

'My boy needs both of his parents in his life and not to live a life undercover, hidden away from his family and the rest of the world.'

He said Christmas was 'unbearable', adding: 'Please, if any members of the public who might have seen Olly or have any information, call the police.'

In another appeal at the end of December he said: 'Every day has been a battle but I know everyone is doing their best to help find my boy.'

A judge raised the alarm in December and urged anyone with information to come forward.

Essex Police are also searching for Ellie and Olly (pictured together) and have urged anyone with information to get in touch

Patrick Sheridan, pictured with his son Olly has appealed for his ex-partner Ellie Yarrow-Saunders to return the child

Mr Justice Williams, who oversaw a hearing in the Family Division of the High Court in London, said he was gravely concerned.

Family court hearings have been staged in private and journalists were barred from identifying relatives involved.

Mr Justice Williams said he has now lifted the identity bar in the hope that publicity will help find Olly and Miss Yarrow-Sanders.

He said the family members from Basildon in Essex could be named and photographs published.

Miss Yarrow-Sanders disappeared before she was due to give evidence in court proceedings

Miss Yarrow-Sanders (pictured with Olly) has 'gone underground', according to lawyers

Lawyers representing Mr Sheridan said Miss Yarrow-Sanders had 'gone underground'.

Staff at law firm Irwin Mitchell said Miss Yarrow-Sanders had not used her bank accounts or mobile since disappearing with Olly.

A spokesman said Miss Yarrow-Sanders's mother travelled to Huddersfield, West Yorkshire, at around the time Olly vanished.

She said Miss Yarrow-Sanders and Olly might also have stayed in the area.

A friend of the family said Miss Yarrow-Sanders ran a cafe with her mother Donna, 47, and first met Mr Sheridan at a pub when she was 18.

Sources close to the family said they had been ‘torn apart’ by the disappearance but added that Miss Yarrow-Sanders was ‘a mum who’s chosen to put her son before anyone else’.

Essex Police have also appealed for anyone with information to get in touch.