Madonna has launched an appeal to find more virgins to enable the continuation of trials for a controversial new therapy.

Inspired by the legendary Countess Bathory, immortalised by actress Ingrid Pitt in the 1970 Hammer film, Countess Dracula, TBI (Total Blood Immersion) therapy, during which patients soak for up to three hours in a bath of plasma heated to a constant temperature of 36 degrees C, can only be effective if the solution used has been harvested from not less than 12 female virgins

Yet to be recognised by NICE, TBI is rumoured to be the source of the glowing skin and youthful appearance of Hollywood A-listers including Sharon Stone, Demi Moore and Michelle Pfeiffer.

Madonna, the only public figure to openly admit her reliance on TBI, is spearheading an international appeal designed to raise awareness of the virgin shortage, while encouraging more young women donors to come forward.

At a press conference yesterday she told reporters: "We aren't living in the middle ages for f**k's sake. We've moved on since then. This isn't about death any more. All I'm asking for is a f**ckin couple of pints. If you are a virgin it's your duty to do a beautiful thing."

She added: "I would like to ask anyone thinking about not being a virgin to take time out and think long and hard about the good they can do with that very precious gift."

Trials have stalled in the US since the last stocks of virgin plasma were exhausted in April. Manufacturers have since attempted to locate alternative sources and are rumoured to be in talks with the Vatican.

Madonna admits that she is close to desperation. "This is a crisis. I am f**ckin scared about what the future might hold."

Manufacturers have confirmed that the status of the blood processed is critical. Studies have shown that contributions from well-meaning sympathisers who are like a virgin have little or no effect.