Top National Hunt trainer Nicky Henderson is due back at the racecourse this weekend after sitting out a three-month ban.

Mr Henderson was suspended by the British Horseracing Authority on 2 July after his horse Moonlit Path, owned by The Queen, tested positive for a banned drug at Huntingdon in February. He was also fined £40,000.

The ban expires on Sunday (11 October) and the trainer has made entries for runners at Ffos Las that day.

Mr Henderson this week told The Times that the experience had made him “feel like a criminal” and was his “worst experience”.

Mr Henderson, whose Lambourn yard Seven Barrows has 150 horses, added he hoped his “reputation had not been damaged” and thanked his owners and staff for their support.

“We’d obeyed the rules faithfully for 30-odd years and then something got into a horse’s system that shouldn’t have been there. What I can categorically say is that nobody was trying to cheat,” he told the paper.

Vet James Main, who administered the drug, is no longer associated with Seven Barrows and stepped down from his position on two BHA committees in July.

Mr Henderson added: “We have no dealings now. James has been a mate for a very long time, but we felt the need to make changes to our veterinary procedures this season.”

The Royal College of Veterinary Surgeons declined to comment on whether Mr Main was being investigated.