'No one is judging this woman's action,' says Mary Asprey, of the Missing Persons Bureau, 'but we think someone should be looking for her. She may be in the Thames for all we know. She needs to be found, just so she has the chance to say: 'My husband beats me up' or 'I love him, I'm going home'.'
Current estimates put the number of missing people in Britain at 250,000. The police say they simply have not got the resources or manpower to look for them all. Unless your missing relative is classed as 'vulnerable' (ie, under 18 or mentally ill), or foul play is suspected, you could walk into a police station tomorrow and be told: 'Sorry, there's nothing we can do.'
This is the gap that the Missing Persons Bureau aims to fill. Set up originally as a helpline in 1989 by two senior policemen and two members of the Suzy Lamplugh Trust, the charitable organisation last year broadened its activities to address this large and growing problem more directly.
Janet Newman, an MPB co-founder, says: 'Having a relative go missing is the worst thing anyone can go through. If someone in your family is ill, then you nurse them. If someone dies, you mourn. But if they are missing for a long period, it's almost impossible to come to terms with because there's no end to the story.'
The MPB deals with, and has on file, thousands of cases at any one time. Since its inception in July 1992, it has found 95 'vulnerables'. The headquarters in south London houses computers with specially designed missing persons software packages. Twenty telephone lines are staffed by 15 part-time volunteers who operate a 24-hour helpline that receives an average of 575 calls a week.
The calls come from relatives of missing persons who need practical information and advice, as well as emotional support. 'Sometimes you come off the phone feeling as if you've been wrung out like a wet dishcloth,' Janet Newman says.
There are innumerable reasons, she explains, why people choose to 'disappear'. 'A typical situation is, say, a man with a wife and children, who is made redundant. He can't find work; he feels he's let them down. He starts to row with his wife and finally he can't take it any more and he leaves.'
However, there are other people whose actions are more mysterious. The MPB dealt with one seemingly happily married woman whose lorry-driver husband went on a trip and simply never came back. After months of anguish she learnt that he had moved abroad.
There was also a case involving a young man who went on holiday to Morocco five years ago, and hasn't been heard of since. His father, by now desperate to know whether he is alive, has been informed that he may have joined the Foreign Legion.
These are not isolated cases. Often, people do not even realise that they are missing, or they simply do not think anyone cares where they are.
In general, the MPB rarely actively traces non-vulnerable people. Staff are keen to distance themselves from the professional 'tracers' and private detectives who charge up to pounds 1,000 to find missing people - usually those who owe money. They say they have found that about half the people who 'disappear' do so leaving large debts.
The main weapon of the MPB is publicity - in the form of 'Have You Seen' posters and appeals in publications such as the Big Issue. Their efforts have been greatly aided by the donation last November of a piece of hi-tech hardware - a computerised 'ageing' machine. This device, a gift from Wang computers, worth pounds 28,000, enables the MPB volunteers to doctor photographs and artificially 'age' a subject's photographic image. The subject's face is divided into a tiny grid. Each small section is then moved or changed slightly. Meanwhile, photographs of parents or other relatives are overlayed. The results have proved to be startlingly accurate. The system can also be used as a Photofit, changing the subject's expression, beard, haircut - even adding a woolly hat if required.
The computer is invaluable, as it is estimated that nearly 100,000 of the 250,000 people reported missing in Britain are under 18. Many are runaways, often fleeing violence, family troubles and sometimes sexual abuse. Many of them end up in London.
'Whatever their reasons for running away,' Mary Asprey explains. 'If they're not found quickly, they can run into far worse situations than they ever dreamt of. By the time they are found they are often very relieved. All it takes is for them to realise, 'Gosh, I'm being looked for - someone does care'.'
Chris Dray, the MPB's 'streetworker', is most involved in finding vulnerables through his network of contacts. Very often, he explains, young people arriving in London will be taken under the wing of a network of homeless people or other runaways. The unlucky ones will become the victims of violence, alcohol and drug abuse, or sexual exploitation.
Mary Asprey and her colleagues are constantly asking themselves whether people should be allowed to remain missing. 'We firmly believe that ethically, everyone has the right to go missing,' she says. 'We would never force someone to get in contact with their family, or tell the family where they are. We would just let them know that people are worried about them, miss them and would love to hear from them.
'Usually, they are delighted - though people do call us to say: 'Leave me alone, I don't want to be found'.'
She adds that there is a positive side to the job. 'It can be wonderfully rewarding. We got a call the other day from a man whose mother had been looking for him for seven years. He just said: 'Tell my mum to get in touch - I want to invite her to my wedding'.'
The Missing Persons Bureau Helpline: 081-392 2000.