A retired headmaster who was honoured by the Queen for his services to young people is facing jail after being found guilty of gross indecency with a 14-year-old boy.

John Coatman, 75, of Leyburn Gardens, Croydon, was today convicted of having sexual activity with the teenager in the 1970s following a trial at the Old Bailey.

He was headteacher at St Andrew's Church of England High School at the time and also worked with a Christian youth group, of which the victim was a member.

The abuse came to light in 2014 after the breakdown of the victim's marriage and problems at work, jurors were told.

He told the court earlier this week that Coatman made him feel “safe” and “valued” and he came to see himself as a "willing partner" in the sexual activity.

But as the years went on he came to "understand the reality of what happened to me" and reported it to the police in 2014.

In emotional testimony to jury, the man broke down in tears as he described the alleged abuse taking place on the floor of Coatman’s lounge.

He added: "The reason I said nothing was because I couldn't bring myself to admit that it had happened to me. I didn't want to accept it had happened to me.

"And believe you me I have been tormented by that guilt ever since - that if others had been victims I could have perhaps prevented it."

But Coatman denied the accusations, saying he was "shocked" and "deeply shaken" to be arrested.

Giving evidence in his defence, Coatman told jurors he had worked with around 22,000 young people in his lifetime and this was his first complaint.

He retired in 1998 after 42 years as a teacher and was awarded an MBE in 2012, the court heard.

Describing the day of his arrest in 2014, Coatman said: "The phone was ringing and my immediate thought was one of my young people had had an accident.

"When I got there, I was arrested. It was a complete shock to me. I had no experience of this kind of thing before in my life. I had never had any sort of complaint."

He went on: "I was deeply shaken because over all my years and all the young people I have worked with I have only had tremendous successes and got on very well."

He told jurors that he had devoted himself to being a teacher and "achieved what I was aiming for" when St Andrew's was listed as 16th in a national league table.

Coatman, who described himself as a bachelor, denied the accusation that "rough and tumble" with his accuser had turned sexual.

He told jurors that the only physical activity the young people engaged in was British Bulldog, and he had never been alone with any of them at his home.

The topic of sex did crop up during youth group meetings, but only in reference to passages in the Bible involving "Christian aspects of sexual behaviour", he added.

But the jury rejected these explanations and found Coatman guilty of two counts of gross indecency after four hours and 20 minutes of deliberations.

The defendant, who made no reaction in the dock, was cleared of one charge of buggery.

Following the majority verdict, the jury heard that Coatman was suffering from prostate cancer.

Sentencing was adjourned until Friday, September 30.

Coatman was granted conditional bail, although Judge Richard Hone QC warned that a jail sentence would follow.