A woman who had a six-month relationship with R&B singer R. Kelly at 16 has told his trial that he physically assaulted her after an argument.

Jerhonda Pace, now 28, also said the star videoed them having sex.

She was the first witness in Mr Kelly’s trial on racketeering, sexual abuse and bribery charges in Brooklyn, New York.

He has pleaded not guilty. His lawyer described Ms Pace as a groupie who had stalked Mr Kelly, which she denied.

She told the court the star insisted she dress like a Girl Scout and wept as she read a diary entry aloud to the court: “Rob slapped me three times. If I lied to him again, it’s not going to be an open hand next time.”

She said the incident began when she did not acknowledge Mr Kelly when he entered the room – one of the rules he had allegedly demanded she follow. She was on her phone but said Mr Kelly did not believe her when she told him she was texting her friends.

“That’s when he slapped me and he choked me until I passed out,” Ms Pace told the Federal District Court in Brooklyn. “When I woke up, I was on the floor.”

The court was told he then forced her to perform a sex act before – as she wrote in her diary – she “became fed up with him” and left, ending the relationship.

It was Ms Pace’s second day on the witness stand. She has said she initially told Mr Kelly she was 19, before admitting she was 16 after their first sexual encounter. The age of consent in Chicago, where they were, is 17.

Mr Kelly – full name Robert Sylvester Kelly – faces charges that he was the ringleader of a two-decade-long scheme where he recruited women and underage girls for sex.

If he is convicted on all counts he could be sentenced to several decades in prison.

His legal team has suggested Ms Pace had previously been a “groupie” who waited outside his home and his 2008 child pornography trial, when he was acquitted. They also depicted her as a jealous “super-fan” who concocted lies.

In her opening argument on Wednesday, Mr Kelly’s lawyer Nicole Blank Becker claimed the alleged victims were aggrieved fans who originally consented to sex before later becoming “spiteful”.

Several accusers
The singer is best known for hits including I Believe I Can Fly, Bump n’ Grind and If I Could Turn Back the Hands of Time.

Ms Pace is one of several accusers who are expected to take the stand over the next month.

She also claimed Mr Kelly knowingly gave her herpes, and on Thursday, Dr Kris McGrath told jurors he had been prescribing herpes medication for Kelly since at least 2007.

Prosecutors have claimed the singer used bodyguards, drivers, lawyers and accountants to cover up his alleged crimes, and bribed victims by photographing and filming them having sex and then threatening to release the tapes.

Even if he is acquitted, Mr Kelly still faces sex-related charges in Illinois and Minnesota, where he has also pleaded not guilty.

He has been in jail for the last two years and was moved in June to Brooklyn from Chicago for the trial.