The Spectre of East German doping returned to haunt German sports yesterday with news that prosecutors have launched a probe into the head coach of the country's world championship swimming team.

The Berlin prosecutors' office, which deals with crimes relating to German unification, said it was investigating Winfried Leopold on suspicion he gave banned substances to swimmers during his time as an East German coach.

The timing could hardly have been worse for the German Swimming Federation (DSV) team headed by Leopold which is scheduled to leave for the world championships in Perth, Australia, later this week.

But DSV president Ruediger Tretow insisted news of the probe would not have any effect on the position of Leopold, who admitted several years ago that he was involved in doping.

"Winfried Leopold will make the journey on Tuesday to the world championships in Perth as team boss," Tretow said. "We see no need for any new action with regard to our team boss."

Prosecutors accuse Leopold of being involved in providing banned substances to swimmers between 1986 and 1990 without telling them or sufficiently explaining the side-effects.

"I admitted in 1991 that I came into contact with doping in East Germany. The letter is really just a result of that," said Leopold, who has renounced doping completely.

The probe is the latest in a series launched by prosecutors into sports coaching in East Germany. The DSV has vowed it will not take any coaches to Perth who are charged with East German doping offences.