Middlesborough-born Campbell scored 16 goals in 74 appearances for Rovers between 2000 and 2002.
His current club, League Two side Barrow AFC, put out a statement earlier today revealing the footballer has died.
They said: “The club is extremely shocked and saddened to hear of the passing of former player Neil Campbell at the age of just 45.
“Campbell scored 27 goals in 76 appearances for The Bluebirds after being signed for the club by Lee Turnbull in 2003.
“Perhaps his most famous goal for Barrow turned out to be the winner in the UniBond Presidents Cup Final at Workington in April 2004.”
The statement added: “Our thoughts and sincere condolences are with his family and friends at this incredibly sad time.”