( CNN ) -- A hacker 's leak of nude photos of Jennifer Lawrence and other female celebrities is now a case for the FBI . Nude photographs of Lawrence , who won an Academy Award last year for her role in `` Silver Linings Playbook , '' were splashed on various sites Sunday . They appeared on 4chan , Reddit , Twitter and Tumblr , among others . Kate Upton 's lawyer confirmed photos of the model-actress were among those leaked , calling it `` an outrageous violation '' of her privacy . `` We intend to pursue anyone disseminating or duplicating these illegally obtained images to the fullest extent possible , '' attorney Lawrence Shire said . Lawrence 's publicist said `` authorities have been contacted and will prosecute anyone who posts the stolen photos of Jennifer Lawrence . '' Some of the alleged victims in the celebrity hacking case `` have engaged with the FBI , '' a U.S. official told CNN 's Pamela Brown Monday . The Los Angeles office of the FBI successfully investigated another hacker who stole nude photos , scripts and personal information from the e-mail accounts of entertainers including Scarlett Johansson , Mila Kunis and Christina Aguilera in 2011 . `` The FBI is aware of the allegations concerning computer intrusionsÂ and the unlawful release of material involving high profile individuals , and is addressing the matter , '' FBI spokeswoman Laura Eimiller said Monday . `` Any further comment would be inappropriate at this time . '' Who 's at fault over nude photo hack . The previous case , which resulted in a Florida man being sentenced to 10 years in prison , involved hacking through the `` forgot my password '' function on celebrity e-mail accounts . Cyber-security experts are now pointing the finger at a flaw in Apple 's `` Find My Phone '' app that opened access to celebrities ' data stored in iCloud . Apple confirmed to CNN Monday that it is looking into reports that its popular iCloud online data backup service may have been compromised by the hackers . `` We takeÂ user privacy very seriously and are actively investigating this report , '' Â Apple spokeswoman Natalie Kerris said .
NEW : Some celebs `` have engaged with the FBI '' about the hacking , a U.S. official says . Apple says company is `` actively investigating this report '' Online posts show nude photographs of actress Jennifer Lawrence . The photos were posted on Twitter and Instagram by hackers who call themselves "Guccifer 2.0 " or "Romanian Hackers" -- but they are not believed to be connected to Russian intelligence agencies.