The discovery of human bones during pipeline-laying work has led to a police appeal for local knowledge of unsolved crime.

A femur - which could date back to the 1950s - was unearthed on land in Lower St Clears last week. Further investigations brought to light more bones. All were in a metre-wide trench, 40 metres long, in the centre of a field near Gwaefi Farm, close to the St Clears Boating Club.

The first bone was found last week by contractors laying the natural gas pipeline serving the Milford Haven LNG terminal.

Work was suspended on the site on Thursday as police cordoned off the area to preserve the scene, and called in a forensic archaeologist and a Home Office pathologist.

A fingertip search of the trench area and the topsoil which had been removed yielded further human remains', police confirmed on Monday. House-to-house inquiries are continuing throughout the area.

Said the senior investigating officer in the case, Detective Chief Inspector Martin Davies: "This is not an archaeological site, so there is no reason why there should be human remains here. We are going through our records of missing persons, and are appealing to local people to come forward with any knowledge they may have about this location or aware of anyone who has gone missing from the St Clears area since."

Said DCI Davies: "Around the femur bone were found artefacts such as bottles, shoes, batteries and household waste which would appear to date back to the 1950s.

"We don't know if we are looking at an informal rubbish tip, or something more sinister, although it appears that these fields were used to deposit rubbish some time after 1952."

The initial examination of the site has now been completed by police, and the human remains will be examined by forensic experts.

"They will assist police in identifying the age and sex of the remains, and attempt to establish the cause of death and an estimate of the period of time since death," added a police spokesman.

A spokesman for the National Grid, on behalf of contractors working for Nacap Land and Marine, assured that archaeological investigation is an integral feature of the mammoth job to lay the pipeline.

Anyone with information can contact the incident room at Carmarthen police station on 0845 3302000.