Google is facing yet another challenge over privacy rights--this one to be played out in a Spanish courtroom, starting tomorrow.

The search giant is up against a legal test from the Spanish government's data protection agency. Established to field complaints from citizens over how their personal information appears online, the agency has demanded that Google remove links to sites that it claims violate people's privacy rigths, according to The Wall Street Journal.

The agency contends that under Spanish law, Google is required to remove such links--a claim that Google has challenged. Specifically, the agency wants more than 90 online articles to be deleted from Google's search engine in response to requests from citizens who object to having their personal information appear among search results.

In an e-mail to CNET, the agency said the cases involve the publication of administrative sanctions, notices of financial debt, and details of victims of domestic violence.

Google argues that the agency is off base by requiring search engines to remove such data rather than asking the actual newspapers and other Web sites to remove the information. The company also has pointed out that other countries go after the actual sources of the data, not the search engines.

"We are disappointed by the actions of the Spanish privacy regulator," Peter Barron, Google's director of external relations for Europe, said in a statement e-mailed to CNET. "Spanish and European law rightly hold the publisher of material responsible for its content. Requiring intermediaries like search engines to censor material published by others would have a profound chilling effect on free expression without protecting people's privacy."

In response to the question of why it doesn't target the actual sources, the agency told CNET that the privacy laws can run into conflict with freedom of expression.

"In this context, the problem arises when the page that hosts the information cannot erase the data because there is a law that protects the publication or a conflict with another fundamental right (freedom of expression), as it happens mainly in cases of official gazettes and media," the agency said.