Ricky Yiu Poon-fai has never won a premiership but he is well-known as the trainer of former three-time world champion sprinter Sacred Kingdom, who was also Hong Kong’s Horse of the Year in 2009-10, and won the inaugural international Hong Kong Sprint with Fairy King Prawn.

Yiu, 55, was also the first Chinese trainer to have won at Group One level on foreign soil, taking out the Sprinters Stakes in Japan with Ultra Fantasy and the KrisFlyer Sprint in Singapore with Sacred Kingdom.

Yiu is having a successful 2012-13 season, with 34 wins, and is equal seventh in the 24-strong trainers’ championship in Hong Kong. But he is likely to lose two of those wins after Yat Ding Win and Legend Express returned positive drugs tests following their victories on June 2.

Yiu has had incidents with drugs before – some of them bizarre.

In 2011, he had a contamination case with Shahjee returning a ketamine positive. The horse was found to have had contact with the drug via normal daily routines involving his mafoo, who had a previous history of drug use.

In 2008, Yiu was fined HK$50,000 after Rely On Me returned a test showing testosterone that breached the threshold levels, and the stable medication book was found not to be up to date.

 And in 2007, Yiu was fined HK$75,000 when Elfhelm returned a positive to an anti-inflammatory, even though video footage from the stabling area showed the horse had surreptitiously taken a mouthful of feed from another horse which was receiving the treatment.