U.S. authorities have launched an investigation to track down a computer hacker who is alleged to have illegally obtained sensitive financial and personal information about a slew of celebrities, including Beyonce, Jay Z, Paris Hilton and Kim Kardashian.

The unidentified assailant has reportedly posted details regarding the stars' banking, credit cards, social security numbers, car loans and mortgage amounts online - and now agents from the Federal Bureau of Investigation (FBI) are involved.

According to Tmz.com, Ashton Kutcher and Mel Gibson are also among the victims, while U.S. Attorney General Eric Holder and Los Angeles Police Department Chief Charlie Beck have been targeted too.

The hacker allegedly tried to access the finance files of U.S. Vice President Joe Biden and former Secretary of State Hillary Clinton, but failed to obtain much information about the pair.