Officials are investigating two possible instances of cheating and animal welfare abuse at the Great Yorkshire Show, being held this week in Harrogate.

Yorkshire Agricultural Society, which runs the show, said an undisclosed "substance" appears to have been used to improve the appearance of two dairy animals. The possible tampering was discovered during routine checks by vets at the show.  

This is the first time such cheating has been investigated since the event was first held 155 years ago. YAS spokesperson and honorary show director Bill Cowling said that, as it would be at least two weeks before the results of tests are known, "the investigation is ongoing".

The owners of the animals have been informed and will continue to participate in the show, pending the test results. However, if these reveal evidence of malpractice, Mr Cowling said the owners would be stripped of any prizes, forfeit their winnings and potentially be banned from showing cattle in the future.

Speaking at a press conference on Wednesday, Mr Cowling acknowledged that the 'tampering' is "Something that is perceived to be a problem," which he said he is glad show officials are addressing.

Following growing awareness of tactics adopted by some unscrupulous competitors in livestock shows, including pumping cows' udders full of gas before sealing them with glue, leaving the animals in 'severe discomfort' for up to a full day, Defra last year said it would prosecute anyone found to be violating welfare laws in this way.