Apple Inc. (NASDAQ:AAPL) CEO Tim Cook will have to face the plaintiff’s lawyers in a civil lawsuit involving allegations of anti-poaching agreements among several major tech companies, including Apple, Google Inc (NASDAQ:GOOG), Intel Corporation (NASDAQ:INTC) and others. Reuters reports that Judge Lucy Koh has ordered Cook to testify because she feels internal emails at the company will uncover important details in the investigation into the case.

Apple CEO Tim Cook

Currently Koh is trying to decide whether the civil suit should become a class action lawsuit. The case alleges that the tech companies named in the suit agreed to eliminate competition for their employees. If Koh does decide to proceed with the case under class action status, it means the plaintiffs could pursue a bigger settlement.

The judge said it seems that during the period of time when the companies agreed not to poach each other’s clients, the executives at those companies decided that it was easier and potentially less expensive to join forces with each other than deal with each of their individual employees. She called that “the biggest problem for the defendants” but also voiced problems with the plaintiffs’ case. She said one key economic analysis had “holes” in it.

The case stems from the 2009 discovery that Apple and Google had an unofficial agreement to stop poaching employees from each other. The U.S. Department of Justice then launched an antitrust investigation, and during the course of that investigation, it was discovered that Apple co-founder Steve Jobs emailed Google CEO Eric Schmidt and asked him to stop poaching his employees. In 2010 the six companies involved in the investigation settled with the DOJ, barring themselves from future anti-poaching agreements.

Attorneys for the five plaintiffs in the civil case say damages could reach into hundreds of millions of dollars. However an attorney for Adobe Systems Incorporated (NADAQ:ADBE), which is also involved in the case, said there is no evidence that the plaintiffs were impacted by the anti-poaching agreements.

Apple Inc. (NASDAQ:AAPL) has reportedly tried to avoid allowing Cook to testify at all. The company claims that he was COO during the period in question, so he wasn’t involved in the alleged anti-poaching agreements. However Judge Koh ruled that Cool would have to answer questions from attorneys for the plaintiffs for four hours, saying that she finds it “hard to believe” that the company’s COO wouldn’t weigh in on employees’ salaries and compensation.

She has ordered Cook to take the stand in the case because she felt that the attorneys were not scheduling depositions from top executives quickly enough. Google Inc (NASDAQ:GOOG) chairman Eric Schmidt is also expected to be questioned by attorneys for the plaintiffs on Feb. 20, and chief executives from the other tech companies named in the lawsuits were also scheduled for deposition.

Apple Inc. (NASDAQ:AAPL), Google Inc (NASDAQ:GOOG) and the other four defendants in the suit tried to have it dismissed last April, but the judge refused to do so, saying it was likely that they colluded in the allegations.