Andrew Struthers' farm was raided only months after new legislation protecting animals was introduced by his employer.

But a sheriff has ruled the evidence of officers from the Scottish Society for the Prevention of Cruelty to Animals inadmissible, as a search warrant was not obtained to go on to his land near West Linton, Peeblesshire.

As a consequence, the Crown yesterday dropped its prosecution.

The decision has been attacked by the SSPCA, which insisted it had been right to go on to the land because of their concerns about so many animals suffering.

Peebles Sheriff Court heard that people living near Mr Struthers' Deanfoot Farm had contacted the SSPCA after they noticed dead sheep scattered around the fields. Ross Wilkie, a senior SSPCA inspector, visited last January and saw several carcases and lambs in distress. Some had to be destroyed by a vet as their condition was so bad.

But he, along with his boss, Paul Anderson, failed to obtain a search warrant before entering the fields two days later, on 19 January.

The trial began earlier this month but was adjourned for a ruling to be made on the lawfulness of evidence gathered by the SSPCA.

The sheriff, John Horsburgh, has now decided that the officers' evidence should not be allowed.

Mr Struthers, 48, works in the agricultural and land services division of the Scottish Government's environment department.