Dermot Henihan, who was the Chef de Missionof Ireland's team at the Olympics last month, has written a scathing letter to Damian McDonald, the chief executive of HSI, complaining about how he was kept in the dark after Denis Lynch's horse Lantinus (pictured), was one of four to test positive for the banned substance capsaicin.

Henihan wrote: "There are very serious questions to be answered both as to what happened and why.

Lynch was prevented from competing in the Olympic individual showjumping final at Sha Tin Stadium, in Hong Kong, where he had been one of the favourites for a medal.

Henihan claimed that "when this news broke, there was already media knowledge" and that he was "bombarded with telephone calls".

He wrote: "Both the Minister for Sport [Martin Cullen] and the president of the OCI (Olympic Council of Ireland) [Patrick Hickey] had travelled to Hong Kong for the showjumping final and I was not able to provide them with any concrete information for some time. Basically they were ignored.

"All the time it was me calling you on the phone and it should have been the other way round.

"I was able to find out more information on the internet, which was causing yet another dilemma, as I as Chef de Mission was being asked serious questions by the Irish media and both they and the Irish public had the right to some answers, but I did not have the answers from you."

Henihan refered to a press release "promised . . . within 45 minutes at approximately 5.30pm Beijing time.

"Our media officer waited for in excess of four hours for this press release, by which time the whole world knew of the precise situation while we were still best updated by the internet".

Lynch is due to have a hearing at the FEI headquarters in Lausanne today where the details of the case will be investigated.

But Hehihan is angry that the OCI have not been kept fully updated on what was happening.

He wrote: "Since August 21 [the day of the incdent], except for one phone call from you [McDonald] about what had been said on a radio or television interview immediately post the event, neither I nor the Olympic Council of Ireland have heard from yourself or Horse Sport Ireland.

"This is not acceptable.

"To be left completely out of the picture regarding the positive test and the ongoing investigation is not in any way helpful."

It is the second consectutive Olympics that HSI have been caught up in a major doping row.

In Athens four years ago Cian O'Connor was stripped of the gold medal he had won in the individual show jumping after his horse Waterford Crystal tested positive.

Henihan said that HSI's "full co-operation" will be required at a meeting soon to be held in order to ensure "comprehensive and detailed report on this issue" and that he was obliged to write to HSI because "I as Chef de Mission and the Olympic Council of Ireland are being excluded from what is essentially a very serious and unacceptable failure at the Beijing Olympics".

Contact the writer of this story at [email protected]