According to the Sun, Mathias’ contract was terminated after he allegedly refused to play for the club’s reserve side.
The 31-year-old was booted out of a French fourth-tier club after just eight months.
The Guinean international joined Belfort after leaving Slovenian club Tabor Sezana last year.
“We made a bad choice in signing Mathias Pogba,” Belfort president, Jean-Paul Simon, was quoted by the newspaper as saying.
“You could say he was the wrong man for the job.
“Let’s say that we have recently opted to separate by mutual consent.
“I take full responsibility. Plenty of bad decisions have been made this season, and I’m not very happy with what we have done.
“Now, all that matters is avoiding relegation,” he added.