Wales manager Chris Coleman was suspicious about some of the games he managed in Spain and Greece following the recent allegations over match-fixing.
This week, an investigation carried out by Europol found that around 380 games across Europe and another 300 games outside the continent may have been the subject of match-fixing.
Coleman has overseen jobs at Real Sociedad and Larissa prior to his role at Wales, and he felt "something was going on" during his time spent abroad.
He said on Sky Sports News: "I've managed in Spain, I've managed in Greece. Some of the games I've been involved in, I can tell you, wasn't fair.
"Something was going on. You can't pinpoint it, but you know there's something going on because of the decisions that are made during the 90 minutes, or even some of the performances of the opposition. You're scratching your head, bizarre things - so you know there's something not quite right.
"I didn't know anybody that was connected with it, but it was different to what I've been used to."
Coleman, who has also been the manager of Fulham and Coventry, said that he has not witnessed match-fixing in Britain.
He added: "I can honestly say, hand on my heart, and I'm proud to say that in all my experience of managing on our island, I've never been suspicious of anything - never been suspicious of a referee being corrupt, never been suspicious of my own players or the opposition players or the opposition manager, anybody on my staff. I've never ever seen it, honestly.
"Looking at the statistics surrounding the corruption, it is frightening, really, startling, and shameful. We always thought that in football you were always going to get one or two who would try and bend the rules but on that scale is alarming and disappointing."