Google's Larry Page was at the center of criticism as he defended questionable software in its smartphone operating system, Android. Oracle had accused Google of 'stealing' Java software, previously owned by Sun Microsystem and now owned by Oracle.

Page was grilled by Oracle's lawyer David Boies, who had also grilled Microsoft's former CEO Bill Gates in an antitrust lawsuit in the 1990s.

Oracle, the company that owns Java, is seeking hundreds of millions of dollars in damages and royalties. Android runs on more than 300 million devices. The company has called two multi billionaires to the witness stand, including its own CEO Larry Ellison.

According to BusinessWeek, Page looked nervous and denied claims that he saw internal Google documents that Oracle is using to build the case.

Boise's attempts to display exhibits containing inside information on Google were blocked by U.S. District Judge William Alsup, as Page apparently didn't remember seeing them. It's not known what was in the exhibits, but Google's lawyers didn't want the contents to be shown.

Some suggestions on what the exhibit's contents could be are money made from Android since launching the OS in 2008, which Google has never revealed. The company brings in revenue from digital advertising and sales of apps.

Much of the case centered around Google needing to pay a license fee to use Java from 2005. That was the year when Google bought the startup that launched Android and Page brought in Andy Rubin to make Google's services more accessible on mobile devices.

E-mails from 2005 and 2006 from Rubin and other Google employees mentioned the need to license Java to build Android. Oracle bought Sun Microsystems in 2010 for $7.3 billion, and the company claims Google wrongfully used Java language for development of its Android OS.

"We really wanted to use Sun's technology. It would have saved us a lot of time and trouble to use Sun's technology. When we weren't able to have our business partnership, we went down our own path," Page said, when clarifying Google's position on Java.

Oracle claims that Android infringes on 37 copyrights for APIs, as Google hasn't licensed Java unlike other companies such as IBM. While Page revealed Google hasn't licensed Java, he said Java APIs aren't under U.S. law as they're not "creative expression."

(reported by Jonathan Charles, edited by Dave Clark)