A singer from the famous German all-girl band No Angels, which has a Bulgarian member in its line-up, has admitted to having unprotected sex with several partners without warning them she was HIV-positive.

Nadja Benaissa, 28, was speaking at the opening of her trial in the German city of Darmstadt.

"I am so sorry," Benaissa told the court. However, she denied deliberately infecting anyone.

She faces a charge of grievous bodily harm for allegedly infecting one man.

She has also been charged with attempted bodily harm for allegedly having sex with two other men who were not infected.

If convicted, Benaissa faces a prison sentence ranging from six months to 10 years.

After the opening of the trial, German news agency DAPD carried a statement from Benaissa's lawyer admitting she had not handled the HIV virus properly, and conceding she had had unprotected sex.

But the singer said: "No way did I want my partner to be infected."

According to prosecutors, Benaissa knew she was HIV-positive as early as 1999.

A former lover, who is HIV-positive, has said the singer infected him in 2004 and is due to appear in court in Darmstadt as a co-claimant.

The trial is expected to end later this mont.

The other three members of what is believed to be the biggest-selling German girlband to date, including Bulgarian Lucy Diakovska, have been summoned to testify.