Arsenal boss Arsene Wenger has claimed he has managed players who had been "bought" by opponents.
Wenger hit out at referee Martin Hansson over the official's display in the Champions League last-16 first-leg defeat in Porto on Wednesday.
The Frenchman labelled Hansson "incompetent" before seemingly implying he had managed players who had taken bribes to fix games.
Hansson allowed Porto to take a free-kick quickly while Arsenal goalkeeper Lukasz Fabianski had his back turned after initially handing the ball to the referee when he conceded a free-kick for picking up the ball from a back pass, and the home side ended up 2-1 winners.
"I believe he is incompetent or dishonest, so I prefer to believe he is not competent," Wenger said of the Swedish referee.
He added: "I have seen much worse than that in my life -- my own players were bought by the opponent. And I didn't become paranoid."
The former Nancy, Monaco and Nagoya Grampus Eight coach did not give any details over the club or players concerned, however.
"I do not want to come out on the past," he said. "In my job, you always have reasons to become paranoid, so I do not want to go the way to think that people are not honest."