The National Horseracing Authority has moved to lessen the growing rumour and speculation about the number of dope test positives by releasing the figures. It is also stepping up the testing.

But the increase in the number of samples returned positive is disturbing – 18 so far this year compared with only five in the whole of the 2013/14 season and nine the previous season.

NHA chief executive Colin Hall said: “Of the 18 specimens which were found to contain prohibited substances, 12 were specimens taken immediately after the race, two shortly before the race and four from horses which were not entered to race – ‘out of competition’ specimens as they are commonly known.

“The NHA has increased the number of out of competition and pre-race tests being conducted.”

Only six of this year’s 18 cases have got as far as a completed inquiry and the NHA will not release the details of the remainder until they reach that stage, with Hall explaining: “Due to the nature of inquiries into the presence of a prohibited substance found in a specimen, some take longer than others and it would be inappropriate to report on the incomplete inquiries at this time.”

The matter was brought out into the open when the Sporting Post published an email sent to Hall by Brett Maselle.

The advocate said: “Rumour is rife in the industry and horseracing websites that a sizeable amount of horses have been found to have prohibited substances in their systems.

“The talk is a trainer has already been fined and a horse suspended as a result of a positive in a Group race, and that a positive has been found in a horse relating to Durban’s biggest race.”

Hall has at least been able to knock the last point on the head, saying: “The NHA can confirm that all specimens taken from horses on 4 July have been tested and no prohibited substances were found by the laboratory.”

Only one of the six completed cases was the result of a pre-race test – the Leon Erasmus-trained Captain Ali who finished sixth at 25-1 at the Vaal in May. This was also the only one in which a substance was found that could be regarded as a stimulant (caffeine).

One of the five post-race positives, 4-1 winner Redcarpet Captain (Gavin van Zyl) at Turffontein in February, showed traces of the antibiotic procaine. Samples of the other four contained anti-inflammatories or pain-relievers – Cool Anne (K.G. Naidoo) 25-1 winner at Greyville in March, Gogetthesheriff (Jacques Strydom) 33-10 winner at Fairview in April, Liquid Ice (Cliffie Miller) 12-1 when last at Flamingo Park in January and Pennington Sands (Tyrone Zackey) 28-10 favourite when fourth at Turffontein in August.

In none of the six cases was there anything in the betting trends to suggest that the horse had been the subject of a gamble. The horses concerned have been disqualified and the trainers fined amounts varying from R20 000 to R60 000.

By Michael Clower