DOG biscuits discovered in a public park in the Borders were later found to have been contaminated with a deadly rat poison.

The incident, at an unspecified location, was one of five recorded in this region last year by the pesticides and wildlife branch of Science and Advice for Scottish Agriculture (SASA).

In July, a member of the public contacted the police after finding the biscuits which contained red-coloured seeds.

According to the SASA report on wildlife poisoning incidents in 2012, published last week, an analytical investigation confirmed the presence in the biscuits of the grain-based rodenticide Difenacoum.

Other species of mammals and birds who prey on affected rodents face exposure to the poison which attacks the liver and pancreas.

However, the SASA report states that the source of the poison was never established.

In another Borders incident in February last year, tests carried out on a buzzard which was found dead by the side of path revealed it had ingested the insecticide Methiocarb.

In April, another buzzard, discovered dead in a field near electricity cables, was found to have the residue of two rodenticides in its liver tissue.

In May, a raven was found dead beside a small piece of meat. A search of the surrounding area discovered the skeletal remains of two rabbits.

In the analytical investigations which followed, the insecticide Bendiocarb was identified in all three carcasses as well as the piece of meat. “The police investigation failed to identify a culprit…and the case is now closed,” states the report.

Finally, in December, 2012, a dog walker found the carcasses of a heron and a badger in a wood. Although it was initially thought they had died of starvation, residues of two anticoagulant rodenticides were confirmed in the liver tissues of both creatures.

The five Borders cases of suspected wildlife poisoning were among 65 recorded across Scotland last year.