A head teacher has told a court a boy who allegedly had sex with a teaching assistant was "upset and shaking" when he revealed the affair.

Kandice Barber, 35, is accused of having sex with the boy, who was 15 at the time, in a field and sending topless pictures of herself to him on Snapchat.

Aylesbury Crown Court heard that Barber was a cover supervisor at the school and was bound by the same rules as teaching staff to not contact students outside school without the head's permission.

The head teacher at the time of the alleged offences, who we are not naming to protect the identity of the victim, told jurors he spoke to the boy in January 2019 after a teacher raised concerns over rumours spreading around the school.

The head said the boy, who cannot be identified for legal reasons, "acted in a surprised way" when the rumours were put to him which he denied were true.

He said Barber "appeared shocked" when he spoke to her about the rumours and she also said they were false.

He read a statement made by Barber shortly after the meeting, in which she said the rumours were "completely not true" and that she was "happily married" with two children.

The statement said the rumours were "sickening and upsetting", adding: "I hope all these rumours are quashed quickly."

No further action was taken by the school, the former head said.

The court heard that he spoke to the boy again in March 2019 when topless pictures of Barber circulated around the school.

The former head, who now works at a different school, told jurors the boy revealed the affair when he spoke to him on that occasion.

"He was struggling to tell us what happened," he said. "He clearly wanted to talk."

He said the boy described how Barber had approached him at a sports presentation in September 2018, took his phone and added herself to his Snapchat.

The following month, the boy said Barber messaged him to say she was dropping off her son and wanted to meet him, the court heard, before they met in a field and had sex.

The head teacher said the boy told him he lied about the affair in January 2019 because Barber had told him she was pregnant with his child.

Describing the boy's demeanour, he said: "He was upset and shaking, he wasn't crying but his hands were shaking.

"He took a long time to explain himself."

The head said he contacted police after speaking to more students and Barber was arrested on March 12.

The court previously heard the boy had changed Barber's name on Snapchat to "Charles" and took screenshots of some of the conversations as evidence of the affair.

Giving evidence by videolink, he said Barber threatened him that if he told anyone about the affair she "was going to bring me down with her".

He denied being "obsessed" with Barber when questioned by defence barrister Nadia Chbat, who had asked him if he sent a message to her saying: "If you don't speak to me watch what happens, you will lose your job and your family."

He replied in court: "No, I never said that."

Barber, of Wendover, denies three counts of causing or inciting a child aged under 16 to engage in a sexual act, one count of sexual communication with a child, one count of causing or inciting a child to engage in sexual activities while in a position of trust, and one count of causing a child to watch a sexual act by a person in a position of trust.

The hearing continues.