Sarah Reilly, the former British international sprinter who switched allegiance to Ireland, was yesterday at the centre of a new dispute between the Olympic Council of Ireland and the Irish Athletics Association. Just hours before her selection for Sydney was due to be approved, the OCI was notified by the International Olympic Committee in Lausanne that Reilly was ineligible to compete for Ireland. It followed the intervention of the British Olympic Committee who, according to an OCI spokesman, raised the matter with the Olympic authorities in Switzerland. "We found ourselves in a position hereby we would have been liable to disciplinary action if we'd gone ahead and selected the athlete," he said.

"Our understanding is that the British Olympic Committee raised the matter with the IOC, pointing out that the athlete was not in possession of an Irish passport and therefore was not qualified to run for Ireland.

Reilly who, under her maiden name of Oxley, represented Britain in category B international fixtures, intimated her intention of competing for Ireland after her marriage to the Irish high-jump record holder, Brendan Reilly.

By rule, an international athlete is not normally entitled to represent another country until an interval of three years has elapsed or in cases where agreement is reached between the national federations concerned, after a year.

It was under this latter clause that the AAI registered Sarah Reilly as an Irish athlete and selected her to compete in an Europa Cup match in June. Predictably, they reacted angrily to this latest development.

"We have a clearance from both the International Amateur Athletics Federation and UK Athletics for the athlete and as such, she is perfectly entitled to run for Ireland in Sydney," said an AAI spokesman.

"Despite claims to the contrary, Olympic track and field competitions are held under the rules of the IAAF and a list of all athletes taking part in the Games must be approved by them. And having cleared Sarah Reilly to compete in the Europa Cup, they had no objection to her running in the Olympics.

"The British Olympic committee takes its specialist advice on track and field from UK Athletics and it mystifies us to be told that this objection originated in Britain." Selection controversies aside, Sonia O'Sullivan will take centre stage when the National Championships at Santry over the weekend bring all our Olympic contenders together for the showpiece of the domestic season.

Although the composition of the squad for Sydney is now almost complete, those on the fringes still cling to the hope that if they can attain an A qualifying standard, there may yet be a late reprieve.

For those already selected, the spur is a big performance to boost self belief before embarking on the journey to the pre-Olympic training camp at Newcastle in Australia, early next week.

O'Sullivan, of course, has already been nominated to lead the Olympic track and field challenge, although she, too, has an important decision to make on her choice of events. And despite the guarded statements of recent weeks, the expectation is that she will declare for both the 5,000 and 10,000 metres. In the intervening period, the emphasis will be on speed work and towards this end, she will view the 800 and 1500 metres programme as a timely opportunity of making some pertinent statements over the next two days.

Originally, she had planned to compete only at the shorter distance but with this event likely to be staged as a straight final, she has now decided to double at 1500 metres.

Among those aggrieved by the Olympic selection process are Una English and Maria McCambride and they will be hoping for big runs in the 5,000 metres to suubstantiate their point.

Like O'Sulivan, Mark Carroll is set to make his seasonal debut in Ireland, probably in the 5,000 metres. Last season Carroll delivered a telling riposte to those who doubted his commitment to domestic athletics with an admirable 1500 and 5000 metres double.

Now he has decided to concentrate on the longer distance and wait for the Grand Prix meeting in Berlin on September 1st, to test his current form at 1500 metres.