Google says that it has caught Microsoft’s search engine copying its results and displaying them as its own, after running a sting operation.

“I’ve spent my career in pursuit of a good search engine,” says Google’s Amit Singhal, who oversees the search engine’s ranking algorithm. “I’ve got no problem with a competitor developing an innovative algorithm. But copying is not innovation, in my book.”

In a response which doesn’t seem to deny Google’s claim, Stefan Weitz, Director of Microsoft Bing, told Search Engine Land, “As you might imagine, we use multiple signals and approaches when we think about ranking, but like the rest of the players in this industry, we’re not going to go deep and detailed in how we do it.”

Singhal calls it cheating, plain and simple.

“It’s cheating to me because we work incredibly hard and have done so for years but they just get there based on our hard work," he said. "I don’t know how else to call it but plain and simple cheating. Another analogy is that it’s like running a marathon and carrying someone else on your back, who jumps off just before the finish line.”

You can read the full report of how the sting was launched here.

Update: Google has since posted its own version of events that led up to the claim here.