The death toll includes 16 red kites. Photo: Brian Scott

Police have revealed that most of the 22 birds of prey killed in the Black Isle were poisoned by a banned substance.

Police Scotland said they were still investigating the deaths of 16 red kites and six buzzards near Conon Bridge in Easter Ross in April.

Tests have revealed 15 of the raptors had ingested an illegal poison. Post-mortem examinations, including toxicology analysis, are being undertaken on the other birds.

A police spokesperson said: “Police Scotland is continuing to work in close collaboration with partner agencies.

“Landowners and farmers in the local area are also continuing to assist police with their ongoing enquiries.

“Police are keen to speak to anyone who has any information about the incident and would encourage them to contact police on 101 or Crimestoppers anonymously on 0800 555 111 or online.

“No personal details are taken, information is not traced or recorded and you will not go to court.”

Rewards totalling £26,000 are on offer for information leading to a successful prosecution of the birds’ killer. The Royal Society for the Protection of Birds, members of the public and landowners have put up the cash.