Gus MacPherson,the St Mirren manager, claimed his side were the victims of an injustice after losing 1-0 to Celtic in controversial circumstances yesterday.

The Paisley side went down to a debatable second-half penalty, scored by Celtic's Barry Robson, and also had defender Will Haining sent off in the 61st minute incident. MacPherson claimed that referee Eddie Smith got the decision wrong and also accused the official of winking at him during the match.

MacPherson was involved in an altercation with the same official in February, when he awarded Celtic an 87th minute free kick which was converted by Shunsuke Nakamura for a 1-0 win.

On the penalty award, he said: "I haven't seen the incident yet but from what I'm told by people I trust, they said Vennegoor of Hesselink was offside and it's a free kick to us. From what I have heard there's contact from Vennegoor of Hesselink on Will Haining. Smith didn't change his opinion regarding the Nakamura free kick last year so there is absolutely no chance he will change his opinion about this.

"There's a lot of questions to be answered but we won't get the answers. It's so, so difficult to say what you feel. We've seen it go on a number of times and you just have to bite your tongue. There's a fine line between winning and losing and sometimes you can't control that."

MacPherson also added: "He Smith was winking to me on the park. He would need to explain that. I don't know if he was trying to irritate us, I don't know what he was doing that for. He'll deny it."

MacPherson also criticised the singling out of managers by referees. "There were pictures of SPL managers on a screen when the referees had their meeting at St Andrews. I don't know the context of it. It might have been completely innocent, but I think it is a dangerous thing to do, to put individual managers on screens. It's worrying. I was one of them."

MacPherson was proud of his side's performance despite the result. "I thought the St Mirren players were outstanding from the first to the last. We worked so hard, had a good shape, passed the ball for good periods and created one or two good chances. If we had maybe got the break that Celtic did then we could have got something from the game. I can't think of a direct save that Mark Howard had to make and he nearly stopped the penalty."