Stephen and Michael McConville have both been banned for three years for attempted doping after they admitted giving banned substances to Anseanachai Cliste before the Foxhunter Chase at Cheltenham on Gold Cup day this year.

The 33/1 chance was scratched by stewards after the discovery of blood-covered syringes in a bag the McConvilles were taking into racecourse stable.

Stephen McConville trains Anseanachai Cliste and his son Michael owns the gelding who had won eight point-to-points in a row up to early March.

The McConvilles issued a statement afterwards: "We fully accept the finding of the British Horseracing Authority and regret that they had to invest time and resources to investigate and address the incident.

"We apologise for what has happened, which was of our own doing due to lack of knowledge. However, this is no excuse for what happened at Cheltenham.

"The horse was administered the tonic - Hemo 15 - which is a widely used nutritional supplement which, unknown to us, contained cobalt.

"We now just wish to put this unfortunate matter behind us as it has caused a lot of stress to all members of our family as the horses and point-to-pointing is purely a hobby for the family. Again, we wish to apologise to the BHA for this unfortunate incident and thank them for the fair hearing."

The early admission of the pair meant the disqualifications were reduced from five years for Michael McConville and from four years for his father Stephen.

Anseanachai Cliste was allowed to continue racing and won the Ulster National nine days after the festival. The positive test for cobalt had not come to light before that win but samples were taken at Downpatrick which the Turf Club here have said returned negative.

This is the first instance of a horse testing positive for levels of cobalt in excess of permitted raceday thresholds in Britain or Ireland since they were adopted by the BHA, and many other racing jurisdictions, in April 2016.

Australia had been hit by a spate of cobalt positives two years ago that resulted in a number of top trainers receiving suspensions. Black Caviar's trainer Peter Moody who was banned for six months, Danny O'Brien was suspended for four years, and Mark Kavanagh, suspended for three. They were subsequently cleared at an appeal that blamed their vet, a decision the racing authorities have challenged.

Cobalt is an essential mineral required by all mammals, including horses but inorganic cobalt salts have the potential to activate the erythropoietin (EPO) gene, which increases production of red blood cells.

Cobalt is present in Vitamin B12, which is present in several veterinary medicines and many equine supplements.

Adrenal Cortex, the other substance involved in the charges, is an anti-inflammatory agent which is not licensed for use in horses in the UK.

The active ingredient is stated to be epinephrine (adrenaline). Epinephrine increases blood flow to skeletal muscles, increases cardiac output and increases blood glucose levels.