Apple Inc said on Friday no customer data was compromised after Australian media reported a teenager had pleaded guilty to hacking into its main computer network, downloading internal files and accessing customer accounts.

The boy, 16, from the southern city of Melbourne, broke into the US computer giant's mainframe from his suburban home many times over a year, The Age newspaper reported, citing statements by the teenager's lawyer in court.

The teen downloaded 90 gigabytes of secure files and accessed customer accounts without exposing his identity, the paper said.

Apple contacted the US Federal Bureau of Investigation when it became aware of the intrusion, The Age said, quoting statements made in court. The FBI then referred the matter to the Australian Federal Police (AFP).

The report said an AFP raid on the boy's family home produced two laptops, a mobile phone and a hard drive that matched the intrusion reported by Apple.

The sensitive documents were saved in a folder called "hacky hack hack", the report said.

It said the boy had boasted about his activities on the mobile messaging service WhatsApp.

An Apple spokesman said the company's information security personnel "discovered the unauthorised access, contained it, and reported the incident to law enforcement" without commenting further on the specifics of the case.

"We ... want to assure our customers that at no point during this incident was their personal data compromised," the spokesman said.

The AFP declined to comment because the matter was before the court. A court spokeswoman also declined to comment other than to say the teenager would be sentenced on Sept. 20.

The boy's name could not be made public because he was a juvenile offender.