The British Horseracing Authority has announced it will conduct a full review of the sport's equine anti-doping rules.

A strict liability rule currently employed by the BHA means the trainer is responsible for any prohibited substance found in a horse in their care, but recent cases involving Philip Hobbs and Hughie Morrison have prompted racing's rulers to look again at the issue.

The BHA admits in its statement "this has called into question some of the assumptions that have been made across the sport about the obligations on those responsible for the welfare of horses and the penalties for breaking the anti-doping rules".

The statement adds the BHA "decided a review is necessary to achieve clarity for all participants, whilst maintaining the commitment to fairness and providing appropriate deterrent to wrong-doing".

Hobbs and Morrison both escaped penalties when they were found not guilty of administration of prohibited drugs found in horses they trained.

Nick Rust, chief executive of the BHA, said the rules needed to be fair to everyone.

"Leading trainers and the NTF have frequently repeated their support for zero-tolerance of prohibited-at-all-times substances.," Rust said.

"The BHA agrees that this is the right approach to adopt if racing is to maintain credibility with the betting and viewing public and ensure a level playing field for participants.

"We need to ensure that our rules are clear about what zero-tolerance means for the obligations on those responsible for horses and the penalties when the rules are broken.

"We want our rules to be fair to all concerned, from trainers who have done nothing wrong through to the punters who need to have confidence that racing is clean.

"We need to make sure that there is an appropriate deterrent for those who might consider cheating, so that we can protect the interests of their fellow participants - trainers, owners and riders - and the betting public."