Yahoo has lost a key employee to Google, a new report claims.

All Things Digital reported yesterday that Prabhakar Raghavan, Yahoo Labs unit chief and the company's head of search strategy, has left the online giant. In a follow-up statement to All Things Digital, Yahoo confirmed Raghavan's departure and thanked him for his work over the last seven years.

Although Yahoo made no mention of where Raghavan was going, All Things Digital cited sources claiming he was on his way to Google to fill an undisclosed position.

Raghavan was heavily involved in a host of Yahoo projects over the years. In 2009, he spoke with CNET about his goal of moving Yahoo Search from a document-focused service to one that anticipates user actions.

"It's time to kill the 10 blue links," he said, referring to the typical look of a search results page at the time. "We want to move away from document retrieval as center of search to divining the user's intent."

As the head of Yahoo Labs, Raghavan was heavily involved in a host of other projects, including advertising. Back in 2008, he explained to CNET why he believed his company's BOSS (Build Your Own Search Service) application programming interface (API) would be an important part of the company's advertising strategy.

"We fully expect it to expand the footprint of Yahoo search advertising on the Web," he said. Four years later, the BOSS API is still around.

Raghavan's departure is just the latest shakeup at Yahoo as the company tries to move beyond its tough times. Last year, the company's board fired CEO Carol Bartz and finally replaced her with its new CEO Scott Thompson. That followed reports that Yahoo employees were unhappy at the company and many of them were considering leaving.

"If you're not growing, if you're not giving people challenging things to work on, if you're not holding out the promise of creating some personal wealth during one of the frothiest technology markets in modern history, and if your people don't ultimately believe in your ability to deliver across that whole spectrum, you're toast," former Yahoo employee Greg Cohn told the Wall Street Journal in an interview last year.

There's no telling if Raghavan was one of those folks who wanted more "challenging things to work on."

Google did not immediately respond to CNET's request for comment on its reported new hire.