Full implementation of the British Horseracing Authority's zero-tolerance policy on steroids has been delayed.

The BHA said in a statement the reason for the deferral from New Year's Day until March was to allow more time to work with stakeholders, trainers and owners and to clarify certain elements of the new.

These elements include the definition of a "responsible person" - the individual with the responsibility for ensuring that a horse is not administered with an anabolic steroid at any given time.

These outstanding issues are being resolved in consultation with the Racehorse Owners Association (ROA), National Trainers Federation (NTF) and Thoroughbred Breeders' Association (TBA).

Rupert Arnold, NTF chief executive, said some practical issues remained unresolved but his organisation was committed to the policy.

"We are committed to working with all the parties involved to ensure the rules and procedures achieve the agreed objectives," Arnold said.

The new policy was announced in the wake of last year's Mahmood Al Zarooni scandal when more than a dozen horses were suspended from racing for six months, as well as the case of Newmarket trainer Gerard Butler and the Sungate treatment,

The new rule says a horse must never be administered with an anabolic steroid at any time from birth to retirement and also gives the BHA greater powers in terms of access for testing registered horses.

Horses must also be registered from a younger age, the BHA must be aware of their whereabouts at all times and a more stringent 14-month stand-down period will be imposed for any horses found to have been administered with anabolic steroids.