Korda, who failed to retain the Australian Open title earlier this month, is trying to stop attempts by the International Tennis Federation (ITF) to have its own decision not to ban him overturned.

The 33-year-old Czech Republic player tested positive for the banned steroid nandrolone at Wimbledon last July.

He was stripped of prize money and ranking points but an appeal panel decided not to impose a one-year suspension after he insisted he had no idea how the drug came to be present in a urine sample he submitted in July.

Now the ITF wants to enforce the ban by appealing to the Court of Arbitration for Sport in Switzerland.

The organisation believes its own appeals board was wrong in only docking Mr Korda his ranking points and prize money in December.

A final decision

But Mr Korda's counsel, Mr Charles Flint QC, told the court that the ITF, under its own anti-doping programme, had no right in law to appeal against the decision, which was "final and binding" on both sides.

The ITF argued, he added, that any such decision was only final if not appealed and that, under its rules, the ITF or any player had an "unfettered right" to re-open and re-argue any decision at a full re-hearing in Lausanne.

Mr Flint said: "We say that argument is incompatible with the wording of the anti-doping programme and wholly inconsistent with its code.

"The programme is designed to provide for speedy and final determination of disputes as to allegations of doping before an independent expert committee."

Mr Korda's case is a rarity in tennis which has had only a handful of positive drug tests in the past five years, none involving top players and most covering recreational drugs.