A spokesman for Chippenham Town said: "Karnell's contract with the club has been terminated with immediate effect.
"After consideration of the facts provided by the FA and interviewing Karnell, the board decided that placing bets on Chippenham Town games in which he participated, left the Board and Management Team with a complete lack of trust and confidence in the player and as such amounted to gross misconduct.Chambers was originally suspended by the club while an investigation was launched.
The forward joined Chippenham in March 2018
He last scored on January 4 in a 3-2 defeat to Tonbridge Angels.