Sienna Miller claims topless pics breached her privacy

Miller is claiming that the publication of the pictures violated her right to privacy and breached her confidence. Reports suggest she is demanding £100,000 in damages. Her lawyers in the matter, Carter-Ruck, did not respond to a request for comment.

Miller was pictured on a yacht off Italy's Amalfi coast with Getty, who is married with four children. She claims that the publication invaded her privacy, but privacy law expert William Malcolm of Pinsent Masons, the law firm behind OUT-LAW.COM, said that the question of invasion of privacy was highly dependent on the specific circumstances of the taking of a picture.

"Sienna Miller's case will come down to whether or not the court considers that the photographs were taken in a place where she had a reasonable expecation of privacy," he said.

"Taking photographs with a telephoto lens on a private yacht is akin to transgressing into a private area such as a home or garden, where confidentiality is expected," he said.

Malcolm said, though, that such an expectation would not necessarily be reasonable on the same yacht if it was moored close to shore next to many other vessels.

Other locations would be less likely to be treated as private, he said. "One can liken a public beach to a public street," he said. "A court would be reluctant to offer celebrities protection unless there were particular circumstances."

Miller accepted the offer of a settlement payout earlier this week from the Daily Star. It had published a photograph which it admitted showed her being harassed by paparazzi photographers. She accepted £15,000 in damages plus her costs, plus the publication of an apology in the newspaper.

That apology read: "We accept, as we said in the article, that Ms Miller was extremely harassed and distressed by persistent pursuit and intimidating tactics adopted by numerous paparazzi in seeking to obtain photographs of her, including the very photograph that we published. We apologise to Sienna for publishing this photograph."

Miller is the latest celebrity to seek protection for her privacy in the courts. English law has traditionally had no law of privacy, though a number of rulings based on the law of confidentiality and on article eight of the European Convention on Human Rights have strengthened privacy protection. That article of the Convention protects a citizen's right to a private and family life.

Author JK Rowling took a case against a newspaper and a photography agency over a picture of her family on the street. The Court of Appeal ruled this year that people enjoy the protection of the Convention wherever they have a reasonable expectation of privacy, and that that could happen in ordinary situations, such as on the street.

Another law that celebrities might use to protect their privacy is the law of confidence. The House of Lords ruled in 2007 that a photographer who took secret photographs of the wedding of film stars Catherine Zeta Jones and Michael Douglas had breached a duty of confidence that extended to all those attending the wedding. The photographer sold the pictures to Hello! magazine, while OK! magazine had paid £1 million for the right to publish pictures of the event.

"The point of which one should never lose sight is that OK! had paid £1m for the benefit of the obligation of confidence imposed upon all those present at the wedding in respect of any photographs of the wedding. That was quite clear," said Lord Hoffman in that case's ruling.