A teenage boy collapsed in court today as he gave evidence against a child soap star who allegedly sexually assaulted him when he was just 14-years-old.

The performing arts student, now 17, claims the actor molested him on a ‘weekly basis’ between August and September 2010 at their stage school in an attempt to prove to his girlfriend that he was bisexual.

The teenager had been giving evidence in the witness box for 20 minutes at Blackfriars Crown Court from behind a curtain when a loud thud and what sounded like a fall could be heard from the public gallery.

The courtroom was cleared while the witness received medical treatment.

Court hearing: A 17-year-old child soap star is on trial at Blackfriars Crown Court, pictured, for allegedly molesting a fellow student at a stage school in London over two months in 2010

The judge said he is now considering allowing the boy to give evidence via videolink as the experience appeared to be too much for him.

The actor, who cannot be named as he is underage himself, allegedly attacked the boy while they attended the same stage school in London.

The alleged victim said he had heard the defendant, who was 15 at the time, was ‘jealous’ about his friendship with his girlfriend.

Jurors heard the TV star forced himself on the teenager in a stairwell and in three further attacks he molested his victim in a cellar, male changing room and the men’s toilets.

He now faces three counts of sexual assault and one count of rape on the boy between July and September 2010.

Opening the case at Blackfriars Crown Court, prosecutor Timothy Forster said the 17-year-old actor admits having sexual encounters with the victim but claims it was consensual.

He told the jury of seven men and five women the abuse started after the defendant’s girlfriend, who was also a friend of the victim, asked him if he was gay.

After hearing about their conversation the defendant later approached the victim, who is now 17, and told him: ‘I think I’m bi’.

Mr Forster said: ‘The victim took that to mean he was telling him he was bisexual. He then asked him to come downstairs with him but he refused.

‘The defendant then sent him a picture of his erect penis and asked the victim to send a similar picture in return but he wasn’t interested.

‘The defendant continued to text him saying he had to prove to his girlfriend that he was bi saying he wanted to “do it” with him. And he said that his girlfriend could watch.’

During the first alleged attack at the school in July 2010, where students at the 100-year-old stage school were performing their end of year show, the defendant is said to have forced the victim down a staircase.

The prosecutor continued: ‘Half way down he told him he had to prove [he was bisexual] because his girlfriend had been with a girl so he had to be with a boy.

‘The victim was not interested in returning the defendant’s overtures….there were incidents on a weekly basis, none of which were wanted, but he was scared to stop the defendant doing what he did.’

The stage school then broke up for the summer holidays but when they returned the victim claims the abuse started again.

A few days into the new term he was standing at the urinals in the men’s toilets when the defendant allegedly came in and touched him before trying to sexually assault him.

And when the victim again rejected his advances he sat down and openly masturbated in front of him, it was said.

The actor was arrested in May 2012 as the victim did not initially tell anyone because he felt ‘shocked and ashamed,’ it was said.

The defendant, from Surrey, denies the charges against him. The case continues.