Cook's comments followed hot on the heels of reports in the British media that Brendon McCullum, the captain of New Zealand, had told the International Cricket Council, he'd been approached to underperform by "a hero" in matches back in 2008.
"You know the tell-tale signs," Cook said in an interview with the London Evening Standard published on Monday.
"But you can always do more, can't you, if it is still going on now? It is a worry," the opening batsman added.
"I've been involved already in a high-profile game which has been changed by (corrupt practices), and it cheapens the sport.
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"Clearly, there are more and more cases that seem to be coming up now.
"It makes you incredibly worried. I know from how I play the game, you're trying to protect the values, the traditions and history of the game -- and play it in the right way.
"People have said it's the tip of the iceberg -- and if that's the case and more and more comes out, it will damage the sport.