The Football Association of Thailand has suspended referee Somsak Poosomnuek for using a racist slur to Thai-Ghananian player Abdulkordiri Hamid during a third division game, the FAT said on Wednesday.
"The Football Association of Thailand has suspended the referee from all competitions," the FAT said in a statement.
The suspension will remain in place while a fact-finding investigation is carried out, the statement said.
Hamid's club expressed their support for the player.
"We oppose racism, insults, or insults based on race, religion, or ethnicity," Prachinburi City said.
The referee is accused of using the Thai equivalent of the N-word, and the club said it was "not the first time" the player had faced such remarks on the pitch.
On his personal Facebook page, Hamid posted: "I can speak Thai ... Since you are a referee, you should be calling me with a better word."
Hamid, who speaks fluent Thai, said the referee made the remarks to him during a Thai League 3 match on Sunday.
Vidmar replaces Vidosic
Melbourne City coach Rado Vidosic has been sacked two games into the A-League season and replaced by Aurelio Vidmar.
The Australian side, the sister club of English Premier League giants Manchester City, were thrashed 6-0 by Adelaide United on Sunday following a 2-1 defeat in their season opener against cross-town rivals Western United.
Vidmar takes over as coach for the rest of the season, Melbourne City said.
Vidmar, 56, has previously had spells with Thai clubs Bangkok Glass, BG Pathum United and Bangkok United.
Melbourne City host Buriram United in Group H of the AFC Champions League next week after they beat the Thai champions 2-0 last week.