The FBI says it may have found a way to unlock the San Bernardino attacker's iPhone without Apple's assistance.
A court hearing with Apple scheduled for this week has now been postponed at the request of the US Justice Department.
The department had ordered Apple to help unlock the phone used by San Bernardino gunman Rizwan Farook, so it could find details of the couple's connections with Islamic State.
But Apple has been fighting the order, saying it would set a dangerous precedent.
Farook and his wife killed 14 people in San Bernardino, California, last December, before police fatally shot them.
Prosecutors say "an outside party" had demonstrated a possible way of unlocking the iPhone without the need to seek Apple's help.