On a cold autumn day in 1987, Jasvinder Sanghera was standing by her market stall in Bradford, Yorkshire, when an acquaintance stopped by with some shocking news. Robina, Sanghera’s older sister, had committed suicide.

Sanghera, then 22, was estranged from most of her family: her parents disowned her when she ran away rather than accept an arranged marriage. She and Robina had kept in touch, in secret. Sanghera knew her sister was deeply unhappy and terrified of her husband but, just a few days after they met for the last time, it seems Robina was overcome with despair.

Knowing there was no way out — her parents had suffered Sanghera’s defiance and would be dishonoured if she also left her husband — Robina went upstairs to her bedroom, poured oil over her clothes and set fire to herself. She suffered 80% burns and died a few days later in hospital.

“I was stunned,” says Sanghera. “My beautiful sister, who shone like a star — gone. I felt that someone should be accountable for her death.”

Last week, Sanghera was one of the key speakers at the Crown Prosecution Service’s first conference on honour killings. Ever since her sister’s suicide she has dedicated herself to helping Asian women escape the horrors of forced marriages. Karma Nirvana, the organisation she set up almost a decade ago, now runs a network of refuges for women and children in Derby and Stoke-on-Trent.

The police and the criminal justice system are just waking up to the realities of life for many Asian women in Britain, who are rigidly controlled by their families and who suffer terrible punishments if they step out of line.

The Metropolitan police has decided to review 122 deaths and suspicious disappearances of Asian girls over the past 10 years in an effort to establish how many might be so-called honour killings. The police and the CPS are separately asking coroners around Britain for details of cases in which they suspect women committed suicide after campaigns of violence or harassment.

Asian women aged 16-24 have a suicide rate three times the national average. According to Commander Andy Baker, the head of Scotland Yard’s homicide unit, there is a problem with “chip pan” fires. “We’ve had a number of incidents of young women being badly burnt where there is not a chip pan in sight,” he said.

Until recently there was a reluctance to believe that families could engineer or carry out the murder of one of their own for what, to western minds, seem trivial offences.Two years ago Abdalla Yones, a Kurdish Muslim, was jailed for life for the murder of Heshu, his 16-year-old daughter. Yones was horrified when he discovered she had a boyfriend, a Lebanese Christian, and stabbed her 11 times before cutting her throat.

After her death a letter was found saying: “Bye Dad, sorry I was so much trouble.”

In 1998, just a few minutes’ walk from Karma Nirvana’s headquarters in Derby, Rukhsana Naz, 19, was murdered by her mother and brother. Naz, who underwent an arranged marriage in Pakistan at the age of 15 and had two children, had returned to Britain and become pregnant by her childhood sweetheart. Her mother held her legs while her 22-year-old brother strangled her with a plastic flex.

“What these girls had done may seem like small or forgivable things, but to these families they are not trivial,” says Sanghera. “They will affect how they are treated by their neighbours, the marriageability of their other daughters. To Asian families izzat — honour — is all important.”

The ancient notion that a family’s honour resides in the demure and obedient behaviour of women — and that a stain on the family honour can be expunged by swift punishment or death — is not exclusively Asian. Police have also come across cases from Turkish, Romany, Bosnian, Kosovan and west African families.