Internal emails at Apple, Google, Intel and a number of other high-profile technology companies suggest organisations have been discussing potential anti-poaching agreements, with an apparent intention of dampening competition between companies.
The discovery comes as part of a civil lawsuit filed by five currently unnamed ex-executives of major tech firms.
During yesterday's hearing in San Jose, California, presiding Judge Lucy Koh stated that Apple's CEO Tim Cook will be questioned for up to four hours on his and the company's involvement.
Part of Cook's involvement includes a 2007 instance in which the then-COO of Apple asked Google CEO Eric Schmidt to cease a poaching attempt on an Apple engineer; a move which apparently threatened a Google employee's job.
Schmidt was still an Apple board member at the time.
Apple attempted to have the case thrown out in April 2012, stating that Cook would not have had any influence over anti-poaching discussions as COO. Koh responded that she found it "hard to believe a COO would have no say over salary and compensation for all employees".
Judge Koh is yet to decide whether the case can proceed as a class action, which will give the prosecution greater control to extract larger private settlements, which lawyers estimate could run into hundreds of millions of dollars.
The case is the latest in a string of similar scuffles between big tech companies and the courts.
Back in 2010, Google, Apple, Intel, Adobe, Intel, accounting software firm Intuit and Disney's Pixar division were all invoved in a settlement after a US Justice Department enquiry forced them to shut down agreements between the companies to stop targeting each other's employees for recruitment.
Ebay was also sued last year for an apparently similar deal with Intuit.