Suicide among young Asian women is running at three time the national average - a shocking statistic that may mask an even darker scandal that has until now been almost routinely ignored, often through misguided political correctness

Shafilea Ahmed, 17, had everything to live for - her goal was to become a solicitor. Yet, in February 2004, five months after she disappeared from her home in Warrington, Cheshire, her body was found in a flooded river in Cumbria.

Just before her disappearance, Shafilea had been taken to Pakistan and introduced to a suitor. During the trip, she drank bleach and harmed herself in an apparent cry for help. Last week, the South and East Cumbria coroner's court heard how Shafilea was frightened of being forced into a marriage by her parents, Iftikhar and Farzana Ahmed. They had allegedly beaten her. After Shafilea's disappearance, her parents and five relatives were arrested but later released.

Ian Smith, the coroner, who ruled that she was unlawfully killed, said: "Shafilea was the victim of a very vile murder ... I hope [the police] discover who did it because this young woman has not had justice." Shafilea is not alone. Evidence is growing that worrying numbers of young Asian women in this country are being harmed because of their objections to enforced marriages.

Honour-based violence includes assault, kidnapping and psychological stress that may be a part of a forced marriage. Police estimate that in Britain there are at least a dozen so-called "honour killings" a year, and in London the Metropolitan Police is re-examining more than 100 deaths from the last decade, some reported as suicide. The suicide rate among young Asian women is three times the national average.

Meanwhile around 300 cases of forced marriages, in Britain and in countries such as Turkey, Pakistan and Morocco, are being handled every year by the Forced Marriage Unit, established in 2005 and which is operated jointly by the Home Office and the Foreign and Commonwealth Office.

Honour killings and forced arranged marriages are based more on culture and custom than religious belief. The United Nations defines honour killing as the killing by a family member or a person contracted by the family to undo "the perceived loss of status brought about by actions seen as sexually immodest". Actual or perceived immoral behaviour may include Westernised clothing, flirting, refusing an arranged marriage, falling in love with an "outsider", requesting a divorce, infidelity and, in extremis, a female "allowing" herself to be raped. It's easy to "transgress", as a case in 1998 in a Turkish province made clear when a teenager had her throat cut in the town square because a love ballad was dedicated to her on the local radio. Knowledge of such cases keep other women in line.

The problem in Britain was first raised in the House of Commons in 1999 by Ann Cryer, Labour MP for Keighley, but she was accused of having a vivid imagination and criticised for "demonising" the Asian community. However Ms Cryer knew from her constituency work in West Yorkshire that teenagers were (and are) removed from school and taken to Pakistan to marry. If a young woman refuses, she risks her life. She forfeits her family, is forced to change her identity and goes into hiding, frequently pursued by bounty hunters.

Cryer argues that the number of reported cases of honour-based violence is bound to increase for several different reasons. Firstly, she says, because general awareness is growing. A second factor is demography: the Asian population is more youthful than the population as a whole, so there are more young women who are of marriageable age. The third element is the action of traditionalists within the Asian community who perceive cultural values to be under threat from a Westernised society, so they are stricter still on young women and the men with whom they fall in love.

"The so-called leaders in the Asian communities say the problem is past. It's not. More and more girls are crying out for help," says Cryer. In Britain, protection remains dangerously patchy. Last summer, for instance, an inquiry was launched after a series of police blunders ended in the "honour" killing of Banaz Mahmood.

Mahmood, a Kurd originally from Iraq, told police on at least four occasions that she was going to be killed because she had fallen in love with the "wrong" man. She even gave a list of names. Police dismissed her claims as "melodramatic". Her father, uncle and a third man were later found guilty of her murder. After the case, Detective Inspector Caroline Goode said: "Clearly there is no honour in killing ... "

Only 11 months before Mahmood first voiced her fears, the Government issued guidelines to all the relevant authorities, including police, social services and education, on how to handle honour-based violence. But they appeared to have made little impact.

Political correctness in the form of a desire not to offend certain racial and cultural groups in society has led to young women being denied justice. Soon after she arrived in London 10 years ago, Diana Nammi, an Iraqi Kurd, founder of the Iranian and Kurdish Women's Rights Organisation, followed a case in which a 21-year-old was killed by her father on the grounds of "honour". The father received only a two-year suspended sentence.

"That is wrong and should not be allowed,"  Nammi says unequivocally. "It means judges are putting culture before the value of a woman's life. This isn't about culture. It's about human rights. Each time a woman goes into a police station for help, it's like a lottery," she adds. "Will the officer behind the desk have a good understanding of the issue?"

Later this year, the Government's guidelines will become a statutory duty and, in theory, some consistency in response should be the result. In addition, in September, the Forced Marriages (Civil Protection) Act, passed in 2007, comes into force. It will permit a victim of a forced arranged marriage or a third party to ask the Family Courts, as a civil action, for protection by applying for an injunction.

Women's groups are split. Some want forced marriage to be classified as a crime, and the enforcers punished in law. Others argue that to do so would simply drive the practice further underground. However, injunctions have proved highly unreliable in giving victims of domestic violence proper protection so the fight to criminalise continues.

When Jasvinder Sanghera, now 43, was a young woman she ran away from home in Derby to avoid an arranged marriage. She slept rough on the streets at the age of 16. During her exile, she self-harmed and attempted suicide. Her sister, Robina, killed herself by setting herself alight to escape a violent arranged marriage. Sanghera subsequently founded Karma Nirvana to help other victims, but the organisation, like Nammi's, is starved of resources. It helps 15 new cases a week.

Now a mother of three, Sanghera says: "The new law won't work unless potential victims and those enforcing arranged marriages are aware of it. We approached every secondary school in Derby to ask if we could put up posters about the guidelines. Everyone said ‘no' for fear of upsetting the parents. What we are talking about is violence, kidnapping and intimidation, yet we see very few prosecutions. No one is held to account."

Sanghera quotes the case of a 16-year-old who refused an arranged marriage. She was kidnapped - only to be rescued. She is now in a witness-protection scheme. Her mother and brother were sentenced last November and given two-year suspended sentences.

"What sort of message does that send out?" Sanghera asks. "Young women asking for help too often are failed and disbelieved." She points out that it takes courage to walk away from a family. "Once they leave, they are disowned, isolated and they live with fear, knowing that their families may track them down. We have a database of 220 men and women, survivors, disowned by families and trying to rebuild their lives. That number is increasing every day."

In April, Karma Nirvana launches the Honour Helpline, using specially trained survivors. If funds can be raised, the aim is to open a helpline in every large community in which honour-based violence might be an issue.

Commander Steve Allen, spokesman on the issue for the Association of Chief Police Officers, says: "The challenge we face is to improve awareness and training across the police service, so that the first officer who comes in contact with a victim is the officer who knows what to do. Nothing less will do."