Senior FBI officials wanted the US government to take Apple to court after it refused to hand over text messages linked to a drug and gun investigation, it has been claimed.
A report in the New York Times says top executives at both the FBI and US Justice Department advocated legal action when Apple did not comply with a request.
Investigators at the Justice Department wanted to get hold of text messages sent between to iPhone-using suspects in real time over the summer.
But Apple responded by pointing out that its iMessage system is encrypted and it had no way to comply.