Sienna Miller and Balthazar Getty
07/23/2008 at 02:00 PM EDT
is striking back against two British newspapers and a photo agency for publishing shots of her cavorting
with married actor Balthazar Getty off the Amalfi coast.
The actress accuses them of breach of privacy and has filed suit in London's High Court, her legal representatives confirm to PEOPLE.
Miller and the law firm of Carter-Ruck are taking aim at the photo agency Big Pictures and News International, which publishes the News of the World
newspapers, which ran a series of stories and (scantily clad) pictures of Miller on vacation with the Brothers and Sisters
Getty, 33, recently announced
his separation from wife Rosetta, mother of his four children.
In December, Miller, 26, won a judgment of about $75,000 against The Sun
and The News of the World
for publishing "highly intrusive" photos of her while she was filming a nude scene for the movie Hippie Hippie Shake
. It's believed to be the largest fine ever levied for a photographic invasion of privacy in the U.K.