"Hull City Football Club has now issued legal proceedings against Paul Duffen in the High Court," said the statement.
"This action has been taken to protect the commercial best interests of the football club against the actions undertaken by Paul Duffen while in office at Hull City."
Adam Pearson, whom Duffen had replaced in June 2007, took over again as Hull chairman after Duffen quit in October.
Duffen stood down after pressure mounted on him and manager Phil Brown following the club's poor start to their second season in the top flight.
The club's accounts were then found to be in the red with accountants Deloitte predicting they would have to raise 23 million pounds to balance their books should they be relegated, and 16 million if they survive.
Source: AFP European Edition