Vanished without trace: the children we must never be allowed to forget

She casts her mind back to the sunny afternoon on 23 April, 1976. Like most children on the Bourtreehill estate in Irvine, Donna and Sandy were keen to play outside. As their grandmother sat indoors, the toddler chased his afghan hound, Kissie, into the street. It was the last time anyone ever saw him.

Ms Davidson was only two years old when she followed her big brother out of the family garden in Ayrshire, but she lives with the guilt of being the last person to see him alive.

"I constantly rack my brains to see if there's something I can remember," says the 32-year-old mother of three, "but my memory turns blank."

When the dog returned alone, their grandmother raised the alarm. Police mounted a massive search, but found nothing.

"We were very close and as a wee child I took it really badly," says Ms Davidson.

"For a long time I believed he was coming back. But you realise you will never see him again."

Determined to help other families, Ms Davidson launched a nationwide campaign this week to track down the thousands of children who disappear in Britain each year.

Posters of missing youngsters will be displayed on 450 vans across the country as part of the initiative. The pictures also feature on the police-run website, MissingKids.co.uk

It is estimated that a child disappears every five minutes in the UK, equating to more than 100,000 a year. Some run away, others are forced out of their homes, while others are victims of abductions.

Although most are found, thousands are never located.

Speed is critical in locating missing children, according to campaign groups, and the rapid distribution of a child's photograph can make the difference between a fast recovery or a prolonged search.

Today, Ms Davidson still believes police reluctance to accept Sandy had been abducted led to delays in finding him.

"Time is of the essence, and you have to get the public involved quickly," she says.

"It's too late for Sandy, but if these posters can trigger the public to act, then it could help save a child's life."

Vicky Hamilton

VICKY Hamilton went missing on 10 February, 1991, during a snowstorm, following a visit to her sister Sharon's home in Livingston, West Lothian. The 15-year-old was last seen waiting for a bus in Bathgate to take her back to the family home near Falkirk.

Despite a massive police investigation and nationwide appeal, her body was never found, and detectives believe she was abducted and murdered.

Eleven days after her disappearance, Vicky's purse was found in St Andrew Square, Edinburgh, which was the main bus terminus.

Last year, her family were given fresh hope after police told them that her recovered purse could be tested for DNA.

Relatives hope forensic analysis could provide clues to who she was with on the day she vanished.

Sandy Davidson

ON 23 April, 1976, three-year-old Sandy Davidson and his sister were being looked after by their grandmother on the newly built Bourtreehill estate in Irvine, Ayrshire.

The toddler ran out into the street after the family's pet dog and was never seen again.

Sandy's sister, Donna, was only two when she followed her big brother out of the family garden. When Sandy's dog returned alone, his grandmother raised the alarm.

The family believe police reluctance to accept the little boy had been abducted hampered the inquiry.

Questioned at length by police and close relatives, Donna Davidson's memories of the day's events are vague, but she believes her brother was abducted.

The case has baffled police for three decades, and his family have no idea whether he is alive or dead.

Andrew MacRae and mum Renee

RENEE MacRae and her son, Andrew, were last seen on the afternoon of 12 November, 1976, driving south out of Inverness.

Later that evening, the car was found burnt out in a lay-by on the A9.

Almost every officer in the Highlands took part in a search which continued off and on for a full year, but the pair have never been found.

Mrs MacRae, 36, said she was going to see her sister, who then lived in Kilmarnock.

However, she had arranged to see her lover, Bill McDowell, Andrew's father, although the rendezvous never took place.

Mr McDowell has always denied any involvement in the disappearance of the pair. Police recently said they believed they were closer to solving the mystery.

Damien Nettles

DAMIEN Nettles vanished at about midnight on a stormy night in November 1996, from Gurnard, in the Cowes area of the Isle of Wight. He was last seen in a chip shop but was identified later, alone, on CCTV in the town.

Despite a major police investigation his whereabouts remain unknown. Aged 16 at the time of his disappearance, he was tall and slim for his age. Damien had a great sense of humour and was an accomplished musician, playing guitar and trombone with hopes of starting a band. Known to his friends as "Damo", he also enjoyed bodybuilding, computer games and fishing. In 1996, he was well over 6ft tall and still growing. He had short hair but favoured a longer style, had a small scar under his chin and may now have a "goatee" beard. Police said he had a good relationship with his family and friends.

Sasha McLeish

SASHA McLeish left her home at 8am on her way to school on 23 June this year. The 15-year-old, from Luton, told her family not to worry if she was late home because she was going to a dance club after school. The alarm was raised when she failed to turn up for class and did not attend the youth club later that day.

Bedfordshire Police said it was possible that the young girl had travelled to Harlesden, in north-west London, where it is thought she had a teenage boyfriend. Detective Constable Zara Carr, who is investigating her disappearance, said she was hoping a member of the public would come forward with information.

"Sasha's family are understandably worried sick, and we would appeal to anyone who has seen or heard from Sasha to get in touch."

Moira Anderson

MOIRA Anderson was last seen boarding the Cliftonhill bus in her home town, Coatbridge, at about 5pm on 23 February, 1957.

What began as a routine journey became one of Scotland's most enduring mysteries.

She had run dozens of errands for her grandmother, and this time it was her uncle Jim who had sent her off to the Co-op to buy a box of Black Magic chocolates for her mother's birthday. Dressed in her trademark pixie hat, long woollen socks and gabardine coat, the 11-year-old made the familiar trip to the shop in nearby Laird Street, just a short distance from her grandmother's home in Muiryhall Street. Clutching a few shillings, she hurried down the road. She was never seen again. Although still described by police as a missing person's inquiry, friends and relatives are certain she was abducted and murdered.

Mohammed Jahid Ul-Haque

FIFTEEN-year-old Mohammed Jahid Ul-Haque went missing from his home in Edinburgh on Sunday, 6 August this year.

Lothian and Borders Police believe the teenager may be sleeping rough on the streets of Essex, and there have been unconfirmed sightings of him in the Saffron Walden area, 50 miles from London.

Mohammed is of Asian appearance, about 5ft 2in in height, medium build with short dark hair.

A police spokesman said: "He is a young lad and we do not know if he has found accommodation. We are worried he may be living rough. We would appeal to anyone who may have seen him to contact police."

Detectives believe he may have tried to find a job in the catering trade.

Kenneth Jones

KENNETH Jones was 17 when he vanished from Glenrothes, Fife, in November 1998. He had been learning to play the cornet, just like his father, and the pair had gone to brass band practice together. Allan Jones's last evening with his son had been perfectly ordinary. But, within hours of returning home, Kenneth sneaked out, taking a sports bag and some clothes. He has not been seen since.

When his father got up for work at 8am the next morning, he thought his son was still in bed. Later, his parents presumed he had gone out with friends.

But when their only child failed to return at teatime, they began to worry, and within 24 hours of his disappearance, police were called in.

They carried out a two-day search of woodland near the family's home, but found no trace of Kenneth.

Derek Burns

DEREK Burns disappeared in March 1989. His mother, Diane, and her husband, also Derek, have not seen their son since he was a long-haired 19-year-old growing up in West Calder, West Lothian.

Three years ago, the teenager's case was featured in a special report on Scotland's missing children, and the National Missing Persons Helpline produced an artist's impression of how Derek may look as an adult. For his mother, the drawing is unnerving. The features are familiar, but the face is not instantly recognisable. It looks like someone she knew a long time ago, and yet the face in the sketch is that of her son, shown as he probably looks today, a man in his early 30s.

Derek's parents hope that a member of the public will recognise their son and come forward with clues to his whereabouts.