"This is a personal matter ... and is wholly unrelated to the financial position of the company," SuperGroup said in a statement on Wednesday.
It is a criminal offence for a bankrupt person to act as a company director.
The seller of Superdry jackets, hooded tops and check shirts said it had appointed Nick Wharton, previously chief executive of Dunelm Group and before that chief financial officer of Halfords Group as interim CFO.
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Shares in SuperGroup were trading down 2.8 percent at 984 pence at 0946 GMT, valuing the group at 800 million pounds.
Analyst Freddie George at Cantor said the timing could not be worse, coming less then two weeks after the departure of Chief Operating Officer Susanne Given.
However, George said Wharton was a "safe pair of hands" who should work well with Chief Executive Euan Sutherland.
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Sutherland had more than his fill of boardroom problems in his previous job running the Co-operative Group, resulting in his resignation last year. Wills had been SuperGroup CFO for more than two years when Sutherland joined in October.
Wills had held senior roles at retailers Habitat, Fat Face, New Look and Debenhams and according to SuperGroup's annual report was paid just over 500,000 pounds, including bonus and benefits, in the year to April 26, 2014.
SuperGroup, which had one of the best Christmases on the high street, said trading was in line with previous forecasts.