Sonia O'Sullivan, a double world cross country champion at Marrakesh last year, will not defend her titles at Belfast in March.

It is also unlikely that she will compete in the World Track and Field Championships, the showpiece of the athletics year, at Seville in August.

Speaking in Melbourne yesterday, she said that she intended to take a long break from competition and concentrate her mind on the Sydney Olympics next year.

"That's the main focus of my athletics career at this point - the only prize that really matters," she said. "And hopefully, the rest will help me achieve it."

"Back in 1995, the year before Atlanta, I won pretty much everything that mattered and some people were already prepared to hand me gold medals. But look what happened.

"This time, I'll approach the Games by a different route. By taking time off, I hope to ensure that when I get to Sydney, I'll be fresher and more attuned than was the case in Atlanta."

O'Sullivan went to Melbourne last October with her Australian boyfriend, Nick Bideaux, shortly after completing a memorable year by winning the Great North Run in Newcastle.

Significantly, however, she abandoned plans to go to a training camp at Falls Creek in northern Australia, where she laid so much of the groundwork for her 1998 successes, and is understood to have done little running in the last three months.

Predictably, the organisers of the Belfast event are disappointed. Yet a spokesperson for the organising committee was still able to trace the silver lining.

While it's always nice to have an Irish athlete in contention for a world championship, the great majority of the world's best long distance runners will be in Belfast and that's something everybody should look forward to," he said.

The champion's withdrawal is, of course, accentuated by the absence of Catherina McKiernan who is struggling to be fit for the London marathon on April 20th after undergoing micro-surgery on her knee in November.

Likewise, IAAF officials will be disappointed by her absence from the Seville meeting as it is being billed as a dress rehearsal for Sydney but shorn of the Irish woman's presence, the women's long distance events will now be seriously distorted.

Sonia O'Sullivan (28), has for many, been the most captivating Irish sports personality of the decade. From the highs of her championship and Grand Prix successes to the depths of her trauma in the 1996 Olympic Games in Atlanta, she has never ceased to fascinate the sporting public.

Controversy, too, has never been far removed from her story. Competing in the world championships at Stuttgart in 1993, she was the victim of a dark oriental plot when Chinese athletes hussled her out of a medal in the 3,000 metres final.

Later doping allegations surfaced about the Chinese and while she learned enough from the experience to finish second in the 1,500 metres final, it was small consolation for an athlete who, even at that stage was imposing herself as a major player on the Grand Prix circuit.

Even this, however, did not compare with her ordeal in the Atlanta Olympics in which she travelled to America as favourite for both the 1,500 and 5,000 metres titles after an unbeaten sequence in her preparatory races.

In the event, she won neither, going out in the heats of the 1,500 metres and running off the track with two laps to go in the 5,000 metres final won by her arch rival, Wang Junxia of China.

Later, her dramatic collapse was attributed to illness but this was never fully explained. Subsequently, she parted company with her boyfriend/coach, Kim McDonald but McDonald would remain as her agent for the next two years.

The I997 campaign was another vast disappointment for her but then, at a stage when she had been dismissed by many, as a serious championship contender, she upset the script yet again, by bouncing back for her most successful year.

Now coached by Alan Storey, she belied her lack of cross country experience by winning two titles in Marrakesh, the prelude to an equally astonishing week in Budapest in August.

After two years of deep disillusionment, O'Sullivan had re-established herself as one of the outstanding runners in the world but now, unexpectedly, her career is once more on hold.