The Premier League strugglers agreed an out of court settlement with Duffen earlier this month after accusing him of spending company money for private use during his time in charge.
Under investigation: Former Hull chairman Duffen
Hull City also alleged Duffen's company received payments from agents in return for allowing those same agents to negotiate transfers on the club's behalf.
Duffen arrived at Hull in 2007 leading a consortium that bought out then-owner Pearson and taking charge of a club with no debt.
Having overseen the club's promotion to the Premier League and narrow survival last season, Duffen resigned in October last year amid grave concerns over the club's finances which are believed to have reached debts of more than £40 million.
Pearson, who returned to the club immediately after Duffen's departure, told the club's fans last night the FA will hold their own investigation into Duffen's dealings with agents and player transfers.
He said: 'There will be a little bit of press this weekend about such a potential FA enquiry but from my discussions with the FA, they are quite happy with the way the club is now handling it.
'They know we are working in the best interest of the game and the club.'
Eye of the Tiger: Hull are in 17th, hovering just above the relegation zone
Pearson also revealed at a fans' forum at the KC Stadium that theclub stand to make £100 million over the next three seasons, if theycan avoid the relegation for a second successive season.
Premier League survival: Pearson says staying up is key to Hull's long-term future
The Tigers, who have no game this weekend, currently sit one point above the relegation zone in 17th place.
Last season they survived on the final day, despite losing to Manchester United.
Pearsonadded: 'The thick wedge of another year in the Premier League and twoparachute payments is the best part of £100m. That's how crucial it isto stay up this season.
'If we had that sort of moneycoming into the club and invest it in the right players with our ownyoung players coming through, we can really take this club places.
'Ifwe stay up then the money from Sky next year will be very significantand will allow this club to manage the wage bill and be in a healthyposition in the Premier League for many years.'
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