Hamilton boss Billy Reid has told Celtic they are far from being the only club in the SPL to have decisions go against them this season.
A Celtic source made public the club's concerns about referees ahead of the Old Firm clash at Ibrox on Sunday, telling of their frustration about major decisions after analysing footage - including the last two games against Rangers.
But Reid insisted the Hoops were not the only victims, saying: "You are talking to a guy who has had plenty of decisions go against him in the last six, seven, eight weeks.
"We didn't get that and we were also denied a penalty at Motherwell.
"We all get it. I don't want to get involved in the Old Firm debate because they look after themselves.
"We are a wee small club in the division, let's be honest about it, and it is difficult to put up with.
"But there is no way that any referee is biased. Anybody insinuating that is just absolutely bonkers.
"It's hard enough refereeing a game without going in saying 'I'm going to give Hamilton Accies decisions today'. That just doesn't happen."
Reid does believe referees are influenced by large home crowds, but acknowledges the pressure they are under to perform a difficult role under the spotlight.
He added: "What I will say, we played Hearts at the weekend and there were 13,000 Hearts fans and a couple of hundred Accies fans.
"When they are all shouting for decisions, it does influence the referee. There is no question about that.
"You go to Celtic Park or Ibrox, with 50,000 or 60,000 there, there is no doubt that the shout does influence them.
"But they are working to the best of their ability and they are under real pressure. I don't have a problem with it at all."