Dappy and his N-Dubz bandmates featured on a number one hit last year
N-Dubz star Dappy has apologised to a woman for sending her threatening text messages, after she contacted BBC Radio 1 expressing her dislike for the band.
Chloe Moody texted The Chris Moyles Show while the band were being interviewed, calling them "losers" and labelling Dappy "repulsive".
But she was shocked to receive a message the following day from rapper Dappy saying: "Your [sic] gonna die".
The BBC said Dappy took down Ms Moody's number without producers' knowledge.
As a result of the incident, N-Dubz have been dropped as ambassadors of anti-bullying charity Beatbullying.
Ms Moody, from Boston, Lincolnshire, texted Radio 1 while in the car with her mother.
She said she was "shocked" to receive the text messages and phone calls from the rapper the following day.
"I missed two calls from a number I didn't recognise, so I texted back asking who it was, and I got a text saying 'your gonna die'."
The message went on to say: "U sent a very bad msg towards Ndubz on The Chris Moyels [sic] Show yesterday Morning and for that reason u will never be left alone!!! If u say sorry I will leave you alone."
Ms Moody added: "I was racking my brains trying to work out who it was, as I didn't tell anyone I had texted the radio show.
"I didn't think it would be him because I seriously didn't think he'd be bothered."
When Ms Moody did eventually answer his call she said she faced further insults.
"He was just ranting, saying 'why are you saying this about me?'. If I had had a number one single and got a message from a nobody to a radio station I would not be too concerned. It obviously hit a nerve."
Despite making an apology through his management, who also offered her free N-Dubz concert tickets, Ms Moody said Dappy was yet to text her personally to say sorry.
Mobo-winners N-Dubz - Dappy and his bandmates Tulisa and Fazer - hit the top 10 with their second album, Against All Odds, last month.
They also featured on Tinchy Stryder's chart-topping dance track Number 1 last year.
In a statement, Dappy - real name Dino Contostavlos - said: "I called her in the heat of the moment when I was angry, but that is no excuse for my behaviour.
"I'm genuinely sorry. I'd also like to send my sincerest apologies to Radio 1."
A BBC spokeswoman said: "He must have taken the number down from the production team's text console in the studio.
"We were unaware of this, but will take steps to ensure it doesn't happen again."
Last November, Dappy joined Schools Secretary Ed Balls to launch a Government campaign against "cyber-bullying" over mobile phones and the internet.
At the time, Mr Balls welcomed the release of an N-Dubz track called "RU Cyber Safe" as part of anti-bullying week and hailed the group as "great ambassadors" in the fight against bullies.
On Friday, shadow schools minister Nick Gibb called on Mr Balls to distance himself from the band, calling Dappy's behaviour "completely unacceptable".
Mr Balls responded: "This text message was completely unacceptable and it is right that he has not only apologised, but accepted there was no excuse for his behaviour.
"I know that many artists work with Beatbullying because they genuinely want to use their influence with young people to campaign against bullying.
"But that starts with ensuring their own behaviour sets the right example."
A spokeswoman for the anti-bullying charity said today: "Beatbullying in no way condones this behaviour and we stress that sending any threatening messages of any kind is completely unacceptable."
"Dappy's behaviour is not becoming of an ambassador to young people. We have no further plans to work with the band."