Dr Peter Webbon has announced he is to leave his position as chief executive of the UK Horseracing Regulatory Authority to take up a similar role with the Animal Health Trust.

Peter Webbon, chief executive of the Horseracing Regulatory Authority, this evening announced a full investigation into breaches of security at Aintree that saw an undercover newspaper reporter gain entry to the stable of Grand National favourite Hedgehunter.

Britain's Jockey Club has stressed its commitment to the welfare of racehorses in the wake of a critical report from Animal Aid.