Pamela Exall disappeared on the evening of August 27, 1974 from Digleas Campsite, Snettisham. She was with her brother Peter and his friend.

A major search was undertaken of the area, which included search of underwater pits by police divers, dog handlers and the RAF helicopter, and comprehensive enquiries were conducted with all the surrounding campsites and houses.

Pamela's disappearance was covered by both the national and local press. Pamela's adoptive parents Winnie and Len Exall also made several television appeals. Despite all these efforts Pamela has not been seen or heard of since.

The senior investigating officer at the time considered several possibilities for her disappearance, including being a stranger to the area and becoming lost. She was five feet tall and of very slight build.

It is known that she went for a walk along the local beach at around 11pm that night and may have become cut off by the tide and drowned. She may even have decided to leave of her own volition, leaving no trace of her whereabouts.

Pamela's case was reviewed by Norfolk Constabulary when Pamela's family contacted the cold case team regarding the case of convicted murderer Peter Tobin.

Photographs of jewellery found in Tobin's possession had been placed onto the Crimewatch website and these items looked familiar to the ones Pamela had on her when she disappeared.

The team in charge of the Tobin investigation also had DNA that had not been attributed to anyone, but Tony Deacon said they are not able to confirm or deny whether Tobin has had any involvement in her disappearance.

The DNA was compared to that of Pamela's blood family members - she has siblings in Australia - and was not a match.

This DNA remains on the Missing Persons DNA Database for any future cross-referencing.

Pamela's family have looked at the two pieces of jewellery which they recognised, but these were not identified as belonging to Pamela.

There have been appeals over the years but unfortunately, with the exception of the above, no further evidence has come to light.

Pamela's case will never be closed and Norfolk Constabulary will continue to look at any new information.

Mr Deacon said: 'We should never forget about them - there will always be someone out there who might know something.'

If you have any information about any of the cold cases call Norfolk police on 0845 456 4567 or Crimestoppers on 0800 555 111 or email coldcaseteam@norfolk.pnn.police.uk

Alternatively call Crimestoppers on 0800 555 111.

To view the cold cases log onto the website www.norfolk.police.uk/newsevents/coldcases.aspx