A Florida man has admitted hacking into the email accounts of celebrities including Mila Kunis and Scarlett Johansson.

Christopher Chaney, 35, of Jacksonville, Florida, agreed on Monday to plead guilty to nine felony charges including computer hacking and wiretapping, AP reports.

The plea follows Chaney's arrest in October following a year-long police probe codenamed Operation Hackerazzi, which was sparked by the unauthorised publication of nude pics of female stars on the net.

Prosecutors suspect Chaney broke into the email accounts of more than 50 entertainment luminaries, including Christina Aguilera and Johansson. Nude self-portrait photos of Johansson, which were meant only for her for her then-husband Ryan Reynolds, were leaked online following the hacks.

It seems Chaney guessed the security reset questions of celebrity accounts using publicly available information, the same tactic used to hijack the webmail account of Sarah Palin at the time the former Governor of Alaska was running for vice-president.

Having gained privileged access to a star's email account, Chaney changed the settings so that every email received by the account was forwarded to an address under his control. Chaney subsequently forwarded the celeb photos he received to two gossip websites and another hacker. There is no suggestion that he profited financially from his celebrity hacking hobby, a factor that may count as mitigation when it comes to sentencing.

"Chris has been very cooperative with prosecutors, he's remorseful for any of the harm caused to the stars, and just looks to a resolution of the case," defence attorney Christopher Chestnut told the news agency. ®