Police were told a Bexleyheath Academy pupil was having an affair with an assistant vice-principal at the school a year before action was taken, a court has heard.

Inner London Crown Court was told friends of the girl who was “absolutely obsessed” with 44-year-old married ethics teacher, Stuart Kerner, went to police in 2012 after she told them she had had sex with him in school offices and a cleaners’ cupboard.

Kerner, from Aylesford, is accused of six counts of sexual activity with a child and two counts of sexual activity with a child by a person in a position of trust.

The relationship allegedly took place between March 2011 and November 2012.

The girl, who cannot be named for legal reasons, was 15 and 16 years old at the time.

Inner London Crown Court was shown a police interview from February last year, in which her friend said the pair would “hang around” after school in Kerner's office or in the library.

She also told the court Kerner had first kissed the alleged victim, now 19, around September 2011 and that the pair had had sex at the school in the months following.

She said: "When school ended I would ask her if she was going home she would say, 'no, I'm going to hang out with Mr Kerner.' 

"I thought that was strange.

"She said before anything happened that she had a crush on him. 

"One day she told me she kissed him,  she said, 'I told him I liked him and I kissed him.'

"He shouldn't have done that anyway, he should have said ‘no’ and refused that.

"They started doing more and more sexual things.

"She said they had had sex. It was either in an office or in a cleaners cupboard."

The girl said that she and her friends had initially questioned the allegations but as time went on they began to believe them.

They reported this to police but were told the girl would have to report it herself.

She said: "It seemed far fetched but the more it went on the more it seemed real.

"She didn't seem like she was lying.

"At the time it was what she wanted."

In 2013 the allegations were reported to police again by the girl's stepmother.

The court also heard from Kerner's personal assistant at Bexleyheath Academy, Vanessa Morrison, who said she believed the girl was “absolutely obsessed” with Kerner.

She said: "She would follow him around and ascertain where he was."

Kerner denies all charges.

The trial continues.