In what's set to be one of the biggest-ever patent fights in the tech industry, Oracle has accused Google of infringing several of its Java patents with the development of Android.
In a lawsuit filed in the Northern California federal court, Oracle claims Google infringed seven patents in all with its SDK and its Dalvik virtual machine.
But Google has always said that Dalvik was created through a 'clean room' development.
Oracle acquired the patents with its $5.6 billion takeover of Sun Microsystems in January. One was written by the 'father of Java' James Gosling, who left the company in April.
The complaint describes the Java platform as "one of the most important technologies Oracle acquired with Sun".
The company is asking the court to order the withdrawal of all Android products, block further infringement and pay massive damages because, it says, the infringement was deliberate - Google has hired several Java engineers who were formerly from Sun. Oracle's demanding a jury trial.
"In developing Android, Google knowingly, directly and repeatedly infringed Oracle's Java-related intellectual property. This lawsuit seeks appropriate remedies for their infringement," said Oracle spokesperson Karen Tillman.
Google chief executive Eric Schmidt recently said the company was selling 200,000 Android phones per day.