The Bulgarian Football Association has condemned the seven-match ban imposed on Celtic winger Aleksandar Tonev for racially abusing an opponent.
The 24-year-old winger was found guilty of "excessive misconduct" after an exchange with Aberdeen's Shay Logan.
Celtic insist they will contest the punishment and the Bulgarian FA is backing the player.
"We express our readiness to assist in every possible way... for the truth to be revealed," read a BFA statement.
Tonev, on loan from Aston Villa, has been capped 16 times and the BFU said they will continue to select the former CSKA Sofia player.
"Tonev has always been a role model at the Bulgarian national team and he never violated the principles of fair play in the football game,
"The BFU strongly condemns all forms of racism and xenophobia at football stadiums and will continue its policy of zero tolerance for such events.
"In the case of Aleksandar Tonev, however, we demand to see evidence that he has committed what he's been accused of. Otherwise, we'll consider that the punishment is biased and exaggerated."