FINA, swimming's international governing body, said Ms De Bruin's case, centring on alleged manipulation of a drugs test, was to be tried by its doping panel.

The organisation disclosed that analysis of a second urine sample provided by the 28-year-old swimmer at her Irish home in Co Kilkenny last January, had indicated "suspicion of physical manipulation".

The disciplinary hearing could go ahead next month. But Peter Lennon, the gold medallist's Dublin-based lawyer, said he was "furious" at the FINA move.

'Suspicion of manipulation'

And he declared: "We have told FINA that unless they withdraw all charges on the basis of there being a negative finding in this case, we will be applying to CAS [the Swiss-based Court of Arbitration for Sport] for an injunction.

"If CAS won't take the case - because they may take the view they have no jurisdiction in the matter - we will be applying to the courts in Switzerland."

Mr Lennon told Irish radio the announcement about De Bruin's case had come as a surprise because he had been in touch with FINA all day about the affair.

"More importantly, it confirms there is no doping offence in this particular case.

"In fact, the charges against Michelle Smith De Bruin should be withdrawn."

Mr Lennon said there was nothing specific in the FINA statement - other than a suspicion of manipulation of the sample.