A  teacher has been cleared of having a sexual relationship with a special needs pupil from London.

Teresa McKenzie, 39, had been accused of conducting a 14-month affair with the boy, starting when he was 16.

But after less than an hour of deliberations, a jury at Chester Crown Court returned unanimous not guilty verdicts on all seven charges of sexual activity with a child by a person in a position of trust.

Tears rolled down her cheeks as McKenzie, of Meifod in Powys but formerly of Chester Road, Tarporley heard the verdicts.

Judge Thomas Teague QC immediately told her she was free to leave the dock.

The two-week trial heard claims that Mrs McKenzie had sex with the boy, who cannot be named because of his age, on several occasions, including in the disabled toilets of the British Library.

They met when she began work as deputy headteacher at a Cheshire special school in 2006.

The teenager, now 18, has attention deficit hyperactivity disorder, emotionally disturbed behaviour and oppositional defiant disorder.

The prosecution said she became his “key worker” and he became infatuated and would follow her around “like a lost dog”.

Throughout the trial, the teacher, described in court as “highly respected”, maintained her innocence.

She said the claims were invented by the boy, who was a “fantasist”.

The jury was told that he had previously invented a string of other relationships and sexual encounters and accused family members of sexually abusing him.

Mrs McKenzie, a mother of two, had worked at several schools, including posts in Bristol and Newport, before becoming an English adviser to the local education authority in Manchester.

From there she secured a job at the Cheshire special school in 2006.

Reading from a prepared statement outside court, Mrs McKenzie said it had been a “very traumatic” time for her and her family.

She also thanked her legal team and added: “I am extremely grateful to the jury for seeing the truth of the situation that I was in.

“I was dealing with a deeply disturbed and suicidal teenager who demanded exceptional care and support. I gave him the attention that he deserved in his desperate predicament.

“I knew that I was exposing myself to risk of false accusation. I persevered because I was able to distract him from taking own life.

“This case demonstrates the risk dedicated and committed teachers are prepared to take every day.”