A vet from Fakenham claims he became the victim of an RSPCA smear campaign after he gave expert evidence against the animal welfare charity in court.

Colin Vogel, 67, of Church Lane, has been a vet since 1969 and regularly gives evidence for the defence in animal neglect cases prosecuted by the RSPCA.

But he alleges that his testimony had prompted the charity to report him to the Society of Expert Witnesses, the Law Society and the Royal College of Veterinary Surgeons 'because their view is that vets should not appear as defence experts'.

He has also obtained emails under the Data Protection Act which revealed a worker at the charity described Mr Vogel as the RSPCA's 'arch-enemy'.

Another disclosed email expresses reluctance that no good reason could be found to remove the RSPCA's endorsement of Mr Vogel's horse manual in 2003.

RSPCA chief executive Gavin Grant said any allegations of 'persecution' of vets and defence experts was untrue, adding: 'There is no place for smears or innuendos or inappropriate conduct.'

Mr Vogel said: 'What appears to happen is that if a vet agrees to give evidence for the defence, then they are liable to find themselves subjected to any number of smears that can be dreamt up. I have been referred to as the RSPCA's 'arch enemy' and that sort of attack against professional people should have no place in a charity for animal welfare.

'They say I am biased because, to them, anybody who does not agree with their view must be wrong. It strikes at the very basis of our justice system.'

Mr Vogel said he began giving defence evidence in RSPCA cases in the years following the publication of his RSPCA horse manual in 1995.

The endorsement of the book was removed in 2003.

One of the emails he obtained from the RSPCA concerning this decision says: 'I know it was hoped that we would be able to criticise the content to an extent that we could refuse to be associated with it.

'To my enormous regret I do not think we can easily proceed on those lines. There are a number of minor points which could be raised, but I could find nothing that was wrong or bad from the welfare point of view sufficient to give us a good case. Sorry.'

The RSPCA's chief executive Gavin Grant said he was not familiar with the personal emails which were revealed to him on BBC Radio 4's Face the Facts programme, and that the views expressed were not the views of the charity.

'There's no place for smears or innuendos or inappropriate conduct within the RSPCA,' he said. 'It is untrue that we persecute vets and lawyers who appear for the defence and as defence experts.

'There have been thousands of lawyers taking defence cases against the RSPCA and we have only ever made a complaint about one.'