But now he wants people to know he did not demand back a single penny of the money.
Campbell, 48, captained Harry Redknapp’s side when they won the FA Cup for the first time since World War Two at Wembley in 2008.
But the club plunged into financial disarray soon afterwards as they tumbled towards administration.
Ex-Arsenal and Tottenham defender Campbell was owed £1.67m by Pompey in bonuses and image rights – plus another £200,000 in interest.
However, rather than demand the money back, the star agreed with administrator Andrew Andronikou to defer repayment until Portsmouth were in a better financial position.
In the end, though, Campbell selflessly decided to chalk the debt off completely in a classy gesture to keep the Fratton Park club afloat.
He told the Portsmouth News: “People need to know this because time has passed, but I have been honourable in everything I’ve done.
“I didn’t get my money, I had to let it go. It was more than £1.6m I was entitled to it but I didn’t want to hamper Pompey moving forward.
“Another person could have said, ‘No, I want my money’, but I didn’t. No way. I was honourable and let it go. I didn’t take a penny.
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“I’ve been very generous and perhaps people haven’t appreciated that.
“It was actually more bonuses than image rights, but when they said I couldn’t get it, fine, I’ll walk away. That was out of respect for a fantastic club like Pompey, it should be common knowledge.
“In the end, once I knew the dire situation, I wanted to let it go and take it on the chin.”
Campbell, who was an Invincible at Arsenal and scored in the Champions League final, made 111 Portsmouth appearances between 2006 and 2009 before joining Notts County in a bumper five-year deal – but played just once.
The 73-cap England international added: “I believe I did an amazing job at Pompey as a footballer, but the guys in the accounts department haven’t.
“I stuck to my part of the agreement, I did everything I was entrusted to do and more. I’ve kept us in the Premier League, won the FA Cup, took us into Europe, I did everything right – but they didn’t.
“Pompey and Notts County were two clubs where I lost my money for the love of football, people don’t talk about that enough.
“It was an astronomical deal I signed at Notts County and I let it go. I could have bankrupted the whole club, but just left it.
“People don’t know how honourable I’ve been with Pompey and Notts County. People think I got my money. Are you serious? I got nothing.”