VITAL evidence linking a farm labourer to a double shotgun murder could have been contaminated during storage, it was suggested to a jury.

Key items forensically linking the killing of a Witney couple to the alleged murderer could potentially have suffered cross contamination, Swansea Crown Court heard yesterday.

John Cooper, 66, from Letterston, near Fishguard, denies murdering holidaymakers Peter and Gwenda Dixon, from Moorland Road, Witney, in 1989.

Hea lso denies two other murder charges.

An expert in forensic DNA sequencing admitted he knew that a bag containing an exhibit was found to be open while in storage.

He also acknowledged that two other items were not previously kept in forensically-controlled conditions.

The trial continues.