According to planetfootball.com the 43-year-old chief excecutive of JJB Sports and son-in-law of club chairman Dave Whelan was found hung from a tree in rural farmland north of Clitheroe on Monday.
Local Police have said they are not treating the death as suspicious, and the death looks to be suicide.
Whelan spoke of Sharpe's illness and depression over the last few months.
He said: "He had been suffering with a serious illness, apparently something to do with his stomach.
"He had been to see a doctor on Friday but we don't know what news the surgeon gave him.
"We still don't know what's happened. He obviously couldn't take it anymore and he seems to have just snapped yesterday.
"His illness had been a great depression for him. I will miss him terribly, he was a good son and friend."
A statement was published on the JJB website and reads as follows:
It is with the very deepest regret that we have to announce the death yesterday of Duncan Sharpe, the Chief Executive of JJB Sports PLC and Director of Whelco Holdings Ltd.
We are sure that all the employees of both Companies will join us in offering our sincere condolences to Jayne, Laura, Matthew, David and Paul, to Duncan’s parents and to Dave and Pat Whelan.
His friendly and outgoing personality has made him many friends both in the business and outside work and we know he will be sadly missed by all his colleagues and the people that he has dealt with since he came to Wigan. Duncan’s enthusiasm, energy and knowledge of both businesses, have been a significant factor in the success of JJB and Whelco.
Our thoughts go out to Duncan’s family and we feel sure that they will be given the strength to face the next few days and weeks.
The Latics will wear black armbands as a mark of respect for Duncan Sharpe in Saturday's away game at Plymouth.