The federation had asked for more time to consider new technical evidence which Modahl's lawyers had introduced at short notice - but the chairman of the three-strong appeal panel Robert Reid, QC ruled that the proceedings should continue.
The new evidence, which is being presented on Modahl's behalf by Professor Simon Gaskill is believed to relate to the way her urine sample was handled by the Portuguese testing authorities last summer.
The first day of the appeal yesterday lasted six hours, with evidence being heard from both sides. Tony Ward, the BAF spokesman, predicted that all the evidence would be heard by today, but that there would not be a decision announced until later in the week.
The venue at the Euston Plaza Hotel in London has been reserved again on Friday if more time is required.
Modahl, six months pregnant, was ushered into the hotel half an hour before yesterday's discussions began and left straight afterwards, accompanied by her husband, Vicente.
The former Commonwealth 800 metres champion has always protested her innocence after large quantities of testosterone were detected in a urine sample taken after she competed in Portugal last July.
Last December a five-strong federation panel were unanimous in finding her guilty. The principal witnesses for the federation then are also taking the stand at the appeal.
Gunnell for Gothenburg, page 23Reuse content