Oracle CEO Larry Ellison said Tuesday he could prove that new Hewlett-Packard CEO Leo Apotheker was involved in a scheme to steal intellectual property from Oracle when he was the head of German software maker SAP.

HP&39's new CEO, Leo Apotheker.

The two companies have been battling each other in court for more than three years over a lawsuit in which Oracle has claimed copyright infringement by SAP subsidiary TomorrowNow, which provided updates and support for Oracle products before SAP shut it down in 2008. SAP has already admitted that employees of its TomorrowNow improperly accessed Oracle's computers and downloaded certain Oracle software code and support information but is balking at Oracle's demand for $1 billion or more in damages.

"A major portion of this theft occurred while Mr. Apotheker was CEO of SAP," Ellison said in a statement that challenged HP to make its new chief executive available as a witness. Ellison said that when he accused Apotheker of overseeing the software theft a few weeks ago, HP Chairman Ray Lane came to Apotheker's defense, penning a letter that said, "'Oracle has been litigating this case for years and has never offered any evidence that Mr. Apotheker was involved.' Well, that's what we are planning to do during the trial that starts next Monday."

"I don't think Ray Lane wants to risk Leo Apotheker testifying under oath as to why he allowed the theft of Oracle property to continue for eight months after he was made sole CEO of SAP," Ellison said. "I hope I'm wrong, but my guess is that HP's new chairman, Mr. Lane, will keep HP's new CEO, Mr. Apotheker, far, far away from the courthouse until this trial is over."

HP has denied Apotheker had any direct knowledge of the software theft and characterized Ellison's statement as harassment.

"Oracle had ample opportunity to question Leo during his sworn deposition in October 2008 and chose not to include him as a trial witness until he was named CEO of HP," HP said in a statement. "Given Leo's limited knowledge of and role in the matter, Oracle's last-minute effort to require him to appear live at trial is no more than an effort to harass him and interfere with his duties and responsibilities as HP's CEO."

Apotheker was appointed chief executive at HP in September after a 19-year career at the German software maker, including a brief stint as chief executive from 2008 to 2010. He resigned in February amid turmoil over poor earnings.

Apotheker took over the job vacated by Mark Hurd, who was forced to resign from HP in the midst of a sexual-harassment accusation and expense-reporting scandal. Ellison lashed out at HP's board of directors over Hurd's departure. Hurd was subsequently named co-president of Oracle and appointed to the company's board of directors.

Apotheker is due to start work at his new post Monday--the same day the copyright infringement trial is scheduled to begin.