Steve Jobs looks set to face up to two hours' questioning over an anti-trust suit related to its iPod music players and the iTunes store.
In the Northern District of California district court in San Jose, Magistrate Judge Howard Lloyd said that "Jobs has unique, non-repetitive, firsthand knowledge" about the issue.
This is slightly unusual: generally, CEOs aren't deemed to have such detailed knowledge of the day-to-day operation of their organizations; even if they are, they are only forced to testify if it can be demonstrated that nobody else could do the job as well.
The case centers around allegations that an iPod software update in October 2004 made the devices incompatible with music from RealNetworks' music store - just five days after RealNetworks launched its Harmony technology allowing the musc to be played on an iPod.
It dates back to 2005, when a group of users claimed that this FairPlay software was anything but, restricting iPod users to music purchased from Apple's iTunes store.
Jobs has been on medical leave from Apple since January, suffering from a rare form of cancer, and has appeared in public only rarely since.
The judge ruled that, because of his medical condition, questioning should be limited to two hours, and should cover only the changes made to the software.
The plaintiffs had hoped to be able to question him on other related matters as well, including Apple's decision not to license its FairPlay technology to other companies, Bloomberg reports.