San Francisco, Mar 8 (IANS): An Indian-origin former Apple engineer Arjuna Siva, who is star witness in a patent trial against chip-maker Qualcomm, has decided not to depose before the court on behalf of the iPhone maker.

According to a report in CNET late on Thursday, Siva, who co-invented the technology and should have been named on the patent, was scheduled to testify in the trial but he did not appear.

Apple counsel Juanita Brooks was quoted as saying that "Siva has retained new counsel that has advised him not to answer Apple's questions".

"He isn't intending to appear, but if subpoenaed, he'll testify," Brooks added.

Siva now works for Google. "Apple can still play Siva's video deposition," the report added.

According to Brooks, Siva's new counsel is a former partner at Quinn Emanuel, the law firm representing Qualcomm.

Apple has accused Qualcomm of witness tampering, which the chip-maker has denied.

Entangled in legal battles for years, the two companies are currently fighting over three patents that Qualcomm says Apple infringed in developing some of its iPhones.