Former Airdrie defender Rico Quitongo is making a racial discrimination claim against the club.
The 22-year-old claimed in September last year that he was racially abused by a Diamonds fan during a 0-0 draw against Queen's Park in September, but the New Broomfield club dropped an investigation into the allegation the following month, saying there was "insufficient evidence".
However, an employment tribual are now investigating the case and Quitongo - who left the club to join League One rivals in January - is being supported by PFA Scotland union and the Equality and Human Rights Commission (EHRC).